Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
But it is my place to warn that the bulk of modern peer-reviewed literature regarding the outcomes of human-mediated dispersal is 'tragically flawed'– by the fact that invasion biology's currency is vehement, almost competitive antipathy to its objects of study. The defining anti stance makes invasion biology intuitively and emotionally (thus politically and bureaucratically) appealing. But it also makes it scientifically unsustainable. Are you saying, then, that any scientific discipline in which the overwhelming majority of the researchers have vehement antipathy to one of their objects of study is scientifically unsustainable?
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Are horses exotic or native if they evolved in North America and then subsequently reintroduced? == Randy Bangert On May 12, 2010, at 3:56 PM, James J. Roper wrote: Good question Martin, But, yes, I would remove all of those from any and all natural settings, and keep them on farms, just like you suggested. As for the animals, they are massive conservation problems in their own rights, so I won't go into why we should all be vegetarian - :-| As you say, keep them from running wild. Which reminds me, have any of you seen those pictures of the record sized boars (domestic pigs) that were shot in Georgia a few years ago? Those are certainly an ecological disaster! Cheers, Jim On Wed, May 12, 2010 at 13:57, Martin Meiss mme...@gmail.com wrote: Really, Mr. Roper (the formality is to avoid confusion between the two Jims)? You would favor removal of such exotics from North America as wheat, apples, oranges, horses, cattle, goats, pigs, and honeybees? Wouldn't you settle for trying to keep them from running wild, rather than eliminating them from farmland because they are exotic? Martin 2010/5/12 James J. Roper jjro...@gmail.com Jim, I hope my (perhaps) subtle tongue in cheek comments about invasives has not confused the issue. I completely agree that human caused introductions are to be avoided at all costs, and active eradication of exotics should be undertaken as a default position until a well-developed argument suggests otherwise. As Elton documented long ago, invasives are problems, both ecologically and financially. States and countries spends billions of dollars each year trying to control many exotics. While I think that we can find examples for both, innocuous exotics and maladapted natives, those examples do not support any position taken on exotics. I would also venture to state that even if statistical tests could not identify an exotic, that does NOT mean the exotic is inconsequential. I think in this case, we should assume guilty until proven innocent. After all, nature took millions of years to come up with what we have today, while we can screw that up in less than a decade. We do not have the information required to decide whether an exotic matters in some philosophical moral sense. We should assume that it is a problem, however, as the best default position - avoid introductions at all costs, eradicate when possible. If we use a moral position, that position can be argued endlessly. If we use a pragmatic position - introductions are uncontrolled experiments and uncontrolled experiments should always be avoided because we cannot know how to predict the outcome (and much less control it) - then until someone can really show how great uncontolled experiments are, no argument will be effective against it. Sincerely, Jim James Crants wrote on 12-May-10 13:02: Jim and others, Your last sentence converges on the point I was trying to make: if you compared native species, as a group, against exotic species, as a group, you would find statistically significant ecological differences (ie, trends), even though you would also find numerous exceptions to those trends. A statistically significant trend is not negated by the existence of outliers, any more than the tendency for men to be taller than women is negated by the fact that many women are taller than many men.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
You do remember that the horses that went extinct in North America are not the same ones that came back with the Spaniards? So, yes, they are introduced. However, horses are not really the issue with introduced species, although they are causing animated debates in the few states that have feral herds. On Thu, May 13, 2010 at 10:16, Randy K Bangert bangr...@isu.edu wrote: Are horses exotic or native if they evolved in North America and then subsequently reintroduced? == Randy Bangert
[ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Under the terminology and definitions promoted by leading invasion
biologists including David Richardson and Petr Pyšek, 'alien' species and
their subset 'invasive' species are not routinely identified by their
ecological characteristics. Aliens are identified by subtracting historical
local biotas (meaning species lists) from recent local biotas, then deciding
which positive bits of the difference can plausibly be attributed to
dispersal via human agency. Invasive species are a subset of aliens: those
with the capacity to spread, identified simply by having done so,
somewhere.
Native species are literally those for which we have no record or
'suspicion' of a history of human dispersal. The sole criterion of
nativeness is therefore absence of evidence. Nativeness has nothing to do
with relative fitness, complexity of interactions, diversity yielding
stability, stability yielding diversity or anything else ecological. It has
only to do with reifying a particular view of humans and 'nature'.
On that basis, numerous studies have concluded that 'natives' and 'aliens'
are ecologically different (or not). At best they have shown some ways that
two different species or populations are ecologically different (or not) in
a specific context. That context is often barely defined in ways that
mainly reiterate the labels 'native' and 'alien'.
Comparing 'invading' species with established ones ('native' or 'alien')
confirms that a population new to some context is measurably growing and
spreading, while one less new isn't. The new one is exhibiting fitness under
prevailing conditions. That might (or might not) affect the fitness of
longer established species in in a discretely measurable way. There's no
reason they should be similar.
If we manage to demonstrate a strong effect, we still have to compare it to
a stipulated preference before declaring it desirable (or not). Even claims
about changing rates of change require stipulations. Departure from an
inferred previous rate carries no message in itself. Deciding change is
happening too fast for comfort is more about comfort than ecology.
Consensus on that score is still consensus about comfort.
Endorsing the general claim alien invasive species threaten [something]
stipulates a preference. Such endorsements routinely appear in the
introductions of peer-reviewed papers. Anthropologists or sociologists of
science might call the phrase a disciplinary talisman or password meaning
something besides the sum of its parts. Unfortunately, it also indicates
that the authors and reviewers of such articles share a significant
confirmation bias.
It isn't my place to dictate how anyone should feel about the current (or
any historic) array of human influences on biogeography - but those
influences are prevailing facts of life on this planet. Nor is it mine to
dictate whether anyone should promote fear and loathing of 'aliens' or
'invasives' with inflammatory caricatures. But it is my place to warn that
the bulk of modern peer-reviewed literature regarding the outcomes of
human-mediated dispersal is 'tragically flawed'– by the fact that invasion
biology's currency is vehement, almost competitive antipathy to its objects
of study. The defining anti stance makes invasion biology intuitively and
emotionally (thus politically and bureaucratically) appealing. But it also
makes it scientifically unsustainable.
The situation is becoming so obviously silly and overblown that
environmental journalists have begun contacting me to discuss their
misgivings and explore the issues, rather than asking for quotable quotes.
Think about it.
Matthew K Chew
Assistant Research Professor
Arizona State University School of Life Sciences
ASU Center for Biology Society
PO Box 873301
Tempe, AZ 85287-3301 USA
Tel 480.965.8422
Fax 480.965.8330
mc...@asu.edu or anek...@gmail.com
http://cbs.asu.edu/people/profiles/chew.php
http://asu.academia.edu/MattChew
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Matt has important points. 1. Alien is from somewhere else (that is, it's recent evolutionary history does not include its current location) and natives are from the place where they reside. AFTER that definition, we come to think that aliens are different than residents, and we often find they are (not surprisingly) and are not. Many marine species have unknown historical ranges, so we have no idea where thare are from, and we call those cryptogenic (hidden origins). 2. Whether organisms are bad for being alien is a judgement call, and subjective. Sure, we can say that they cost money, but that only means that they inconvenience us in some way - still subjective. Sure we can say that they change community dynamics, but does the community care? If evolution were allowed to run its course, I am sure that we would all agree than in another million years or so, all the current aliens will have become natives (adapted for where they are, and fitting - in some way - in the community at that time). Thus, the VALUE statements about aliens and invasives are invariably subjective. 3. Politics is about appealing to emotion to justify getting money (and science is often politics). The trend that this breeds is to inflate the value of whatever it is that we want money for. So, how do we justify spending billions on invasive species control? Economically, not scientifically. My objective, scientific reasons for justifying the removal of invasives and alien species are, in fact, subjective. After all, even Elton said it well, although subectively - and I paraphrase - the continued introductions of species will have the net effect of reducing biodiversity, simplifying interactions in nature, and making the world a less interesting place. I can see a future where ecologists study how introduced species have adapted to their adopted homes, how new interactions evolve in communities dominated by introduced species, how biodiversity changes over time with introductions and extinctions. We will have a whole new science of biogeography - rather than Hubbell's Unified Neutral Theory of Biodiversity and Biogeography we will have someone's Unified Neutral Theory if Biodiversity due to Introductions and Extinctions. I can't help but (subjectively) think that such a place will be much poorer than our natural world of today (and I recognize how much poorer our natural world of today is compared to that of Darwin, for example). Cheers, Jim Matt Chew wrote on 13-May-10 11:59: Under the terminology and definitions promoted by leading invasion biologists including David Richardson and Petr Pyšek, 'alien' species and their subset 'invasive' species are not routinely identified by their ecological characteristics. Aliens are identified by subtracting historical local biotas (meaning species lists) from recent local biotas, then deciding which positive bits of the difference can plausibly be attributed to dispersal via human agency. Invasive species are a subset of aliens: those with the capacity to spread, identified simply by having done so, somewhere.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
I would argue the answer to this question is not so cut and dry. Recent genetic evidence paints a more complicated story, and suggests quite close relationship - at least genetically. Weinstock et al. 2005. PLOS Biology Evolution, Systematics, and Phylogeography of Pleistocene Horses in the New World: A Molecular Perspective The rich fossil record of horses has made them a classic example of evolutionary processes. However, while the overall picture of equid evolution is well known, the details are surprisingly poorly understood, especially for the later Pliocene and Pleistocene, c. 3 million to 0.01 million years (Ma) ago, and nowhere more so than in the Americas. There is no consensus on the number of equid species or even the number of lineages that existed in these continents. Likewise, the origin of the endemic South American genus Hippidion is unresolved, as is the phylogenetic position of the “stilt-legged” horses of North America. Using ancient DNA sequences, we show that, in contrast to current models based on morphology and a recent genetic study, Hippidion was phylogenetically close to the caballine (true) horses, with origins considerably more recent than the currently accepted date of c. 10 Ma. Furthermore, we show that stilt-legged horses, commonly regarded as Old World migrants related to the hemionid asses of Asia, were in fact an endemic North American lineage. Finally, our data suggest that there were fewer horse species in late Pleistocene North America than have been named on morphological grounds. Both caballine and stilt-legged lineages may each have comprised a single, wide-ranging species. On May 13, 2010, at 10:12 AM, James J. Roper wrote: You do remember that the horses that went extinct in North America are not the same ones that came back with the Spaniards? So, yes, they are introduced. However, horses are not really the issue with introduced species, although they are causing animated debates in the few states that have feral herds. On Thu, May 13, 2010 at 10:16, Randy K Bangert bangr...@isu.edumailto:bangr...@isu.edu wrote: Are horses exotic or native if they evolved in North America and then subsequently reintroduced? == Randy Bangert C. Josh Donlan MA PhD Director, Advanced Conservation Strategies | http://www.advancedconservation.org Fellow, Cornell University | http://www.eeb.cornell.edu/donlan M: +1 (607) 227-9768 (GMT-6) E: jdon...@advancedconservation.orgmailto:jdon...@advancedconservation.org P: P.O. Box 1201 | Midway, Utah 84049 USA u
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
I don't know that subjectivity is necessarily a bad thing (of course, that is a subjective judgement!), as long as we recognize that we do certain things based on preferences and define/defend what those preferences are. I suppose the problem is that not everyone will have the same preferences. Where things get dangerous is if we misconstrue our subjective preferences as objective facts. Unfortunately, confusion between our subjective preferences (or anti-exotic biases) and the objectively demonstrated impacts of exotic species on ecosystems has sometimes found its way into the scientific literature (e.g., hearsay on the negative effects of tamarisk treated as scientific fact... as Matt Chew and others have demonstrated). Mark D. Dixon Assistant Professor Department of Biology University of South Dakota Vermillion, SD 57069 Phone: (605) 677-6567 Fax: (605) 677-6557 Email: mark.di...@usd.edu -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ecolo...@listserv.umd.edu] On Behalf Of James J. Roper Sent: Thursday, May 13, 2010 11:20 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Matt has important points. 1. Alien is from somewhere else (that is, it's recent evolutionary history does not include its current location) and natives are from the place where they reside. AFTER that definition, we come to think that aliens are different than residents, and we often find they are (not surprisingly) and are not. Many marine species have unknown historical ranges, so we have no idea where thare are from, and we call those cryptogenic (hidden origins). 2. Whether organisms are bad for being alien is a judgement call, and subjective. Sure, we can say that they cost money, but that only means that they inconvenience us in some way - still subjective. Sure we can say that they change community dynamics, but does the community care? If evolution were allowed to run its course, I am sure that we would all agree than in another million years or so, all the current aliens will have become natives (adapted for where they are, and fitting - in some way - in the community at that time). Thus, the VALUE statements about aliens and invasives are invariably subjective. 3. Politics is about appealing to emotion to justify getting money (and science is often politics). The trend that this breeds is to inflate the value of whatever it is that we want money for. So, how do we justify spending billions on invasive species control? Economically, not scientifically. My objective, scientific reasons for justifying the removal of invasives and alien species are, in fact, subjective. After all, even Elton said it well, although subectively - and I paraphrase - the continued introductions of species will have the net effect of reducing biodiversity, simplifying interactions in nature, and making the world a less interesting place. I can see a future where ecologists study how introduced species have adapted to their adopted homes, how new interactions evolve in communities dominated by introduced species, how biodiversity changes over time with introductions and extinctions. We will have a whole new science of biogeography - rather than Hubbell's Unified Neutral Theory of Biodiversity and Biogeography we will have someone's Unified Neutral Theory if Biodiversity due to Introductions and Extinctions. I can't help but (subjectively) think that such a place will be much poorer than our natural world of today (and I recognize how much poorer our natural world of today is compared to that of Darwin, for example). Cheers, Jim Matt Chew wrote on 13-May-10 11:59: Under the terminology and definitions promoted by leading invasion biologists including David Richardson and Petr Pyšek, 'alien' species and their subset 'invasive' species are not routinely identified by their ecological characteristics. Aliens are identified by subtracting historical local biotas (meaning species lists) from recent local biotas, then deciding which positive bits of the difference can plausibly be attributed to dispersal via human agency. Invasive species are a subset of aliens: those with the capacity to spread, identified simply by having done so, somewhere.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
For Phragmites, there was an assumption that it was evil and lots of money spent on removal projects long before we had studied its impacts on marsh ecology, which are not all negative. I don't know that subjectivity is necessarily a bad thing (of course, that is a subjective judgement!), as long as we recognize that we do certain things based on preferences and define/defend what those preferences are. I suppose the problem is that not everyone will have the same preferences. Where things get dangerous is if we misconstrue our subjective preferences as objective facts. Unfortunately, confusion between our subjective preferences (or anti-exotic biases) and the objectively demonstrated impacts of exotic species on ecosystems has sometimes found its way into the scientific literature (e.g., hearsay on the negative effects of tamarisk treated as scientific fact... as Matt Chew and others have demonstrated). Mark D. Dixon Assistant Professor Department of Biology University of South Dakota Vermillion, SD 57069 Phone: (605) 677-6567 Fax: (605) 677-6557 Email: mark.di...@usd.edu -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ecolo...@listserv.umd.edu] On Behalf Of James J. Roper Sent: Thursday, May 13, 2010 11:20 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Matt has important points. 1. Alien is from somewhere else (that is, it's recent evolutionary history does not include its current location) and natives are from the place where they reside. AFTER that definition, we come to think that aliens are different than residents, and we often find they are (not surprisingly) and are not. Many marine species have unknown historical ranges, so we have no idea where thare are from, and we call those cryptogenic (hidden origins). 2. Whether organisms are bad for being alien is a judgement call, and subjective. Sure, we can say that they cost money, but that only means that they inconvenience us in some way - still subjective. Sure we can say that they change community dynamics, but does the community care? If evolution were allowed to run its course, I am sure that we would all agree than in another million years or so, all the current aliens will have become natives (adapted for where they are, and fitting - in some way - in the community at that time). Thus, the VALUE statements about aliens and invasives are invariably subjective. 3. Politics is about appealing to emotion to justify getting money (and science is often politics). The trend that this breeds is to inflate the value of whatever it is that we want money for. So, how do we justify spending billions on invasive species control? Economically, not scientifically. My objective, scientific reasons for justifying the removal of invasives and alien species are, in fact, subjective. After all, even Elton said it well, although subectively - and I paraphrase - the continued introductions of species will have the net effect of reducing biodiversity, simplifying interactions in nature, and making the world a less interesting place. I can see a future where ecologists study how introduced species have adapted to their adopted homes, how new interactions evolve in communities dominated by introduced species, how biodiversity changes over time with introductions and extinctions. We will have a whole new science of biogeography - rather than Hubbell's Unified Neutral Theory of Biodiversity and Biogeography we will have someone's Unified Neutral Theory if Biodiversity due to Introductions and Extinctions. I can't help but (subjectively) think that such a place will be much poorer than our natural world of today (and I recognize how much poorer our natural world of today is compared to that of Darwin, for example). Cheers, Jim Matt Chew wrote on 13-May-10 11:59: Under the terminology and definitions promoted by leading invasion biologists including David Richardson and Petr Pyšek, 'alien' species and their subset 'invasive' species are not routinely identified by their ecological characteristics. Aliens are identified by subtracting historical local biotas (meaning species lists) from recent local biotas, then deciding which positive bits of the difference can plausibly be attributed to dispersal via human agency. Invasive species are a subset of aliens: those with the capacity to spread, identified simply by having done so, somewhere.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Whether natural or cultural, every species takes advantage of opportunities to disperses/migrate to colonize and multiply. And, when they colonize/invade a new place (mostly already occupied), other species that have already there before (e.g., native species) would be affected. Some may adjust, thrive, and advance, while others may become extinct. Eventually, a new ecological community establishes, until another species invade/colonize or environmental condition changes. This is what every species does. Every species has some kind of dispersal mechanisms. Ecological community species interactions/compositions and ecosystem processes are dynamic and ephemeral, while our some of ecological disciplines are based on static perspective where set of communities and species interactions are static, complete, and integral. Nothing wrong with this. Within a limited time frame, they really can be considered static. For instance, many textbook describes the US southeastern oak-hickory forest as primary/virgin/old growth forest, but in reality, the forest was originally chestnut forest before chestnut blight wiped them out in 1900-40s. In decadal timeframe this forest is a stable oak-hickory forest, while in centuries timeframe it is an altered dynamic forest. Now, should chestnut be considered exotic species in this altered forest community? I don't think there is no objective measures to define what is considered I think it is imperative that to clearly state you own working (often subliminal) definition of native/non-native community/species in terms of time/spatial scale. Toshihide Hamachan Hamazaki, PhD : 濱崎俊秀：浜ちゃん Alaska Department of Fish Game Division of Commercial Fisheries 333 Raspberry Rd. Anchorage, Alaska 99518 Ph: 907-267-2158 Fax: 907-267-2442 Cell: 907-440-9934 E-mail: toshihide.hamaz...@alaska.gov
[ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
This has been an especially interesting and worthwhile discussion, particularly on the ethics front. My ethics derive from an ecologist whose name I can no longer recall but whose mantra was that Nature took millions of years to sort out the current state and any human-caused change is, by definition, adverse. Where people have a hand in it, it is bad, regardless of any perceived shot-term benefit. Pedagogical but true in my view. Cordially yours, Geoff Patton, Ph.D. 2208 Parker Ave., Wheaton, MD 20902 301.221.9536 --- On Tue, 5/11/10, James Crants jcra...@gmail.com wrote: From: James Crants jcra...@gmail.com Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To: ECOLOG-L@LISTSERV.UMD.EDU Date: Tuesday, May 11, 2010, 10:47 AM I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more prone to failure than those where any and all ecological outcomes are deemed acceptable, but that's only because failure in the former group means invasion and domination by exotic species, while there is no such thing as failure in the latter group. JC(2) Very-long-distance dispersal by humans confers a fitness advantage over very-long-distance dispersal by other agents, on average, for two reasons. First, humans often disperse organisms in groups, such as containers of seeds, shipments of mature plants and animals, or large populations contained in ballast water, allowing them to overcome the Allee effects (lack of mates, inbreeding depression) their populations would face if introduced as one or a few individuals. We also often take pains to maximize the establishment success of organisms we disperse, by shipping healthy, mature plants and animals and propogating them when they arrive, while non-human dispersal agents usually introduce small numbers of organisms, often nowhere near their peak fitness potential (e.g., seeds, spores, starving and dehydrated animals). MC(2). JC appears to be arguing that once rare occurrences are no longer rare. I agree. But I draw the opposite conclusion, because he is arguing that to generate
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Ecolog: Thanks to everyone who has contributed to this discussion so far. I hope others will continue to weigh in. If I may reemphasize, my question was whether or not CULTURAL (post-domestication) dispersal should be distinguished from non-cultural (pre-civilization) dispersal. Another way of saying it might be dispersal by advanced (nebulous, of course) civilizations. Yes, this is fuzzy, but as Crants pointed out (if I may paraphrase), fuzzy is only fuzzy around the edges. Others have pointed out that it boils down to a matter of degrees, and so the terminology might be that which is actually relevant, not terminology that causes confusion by being overly rigorous. I apologize if I made this distinction too fuzzy (in the familiar form of the term). Preponderance of the evidence might be a track to investigate. If ecology is not a fuzzy phenomenon, would it better be described and being amenable to reductionism? Is significance absolute? At what point do data and terminology become relevant and irrelevant? WT PS: I alternately thank Zadeh and curse him for naming his idea fuzzy. Too rigorous? But he apparently did not (perhaps naively) expect, at least his target audience, to beg the issue interminably. I guess he expected his definition to be accepted. Maybe that's why IBM executives tossed him out and a lot of Japanese welcomed him and his fuzzy ideas. The tool continues to lie neglected, unused for the most part. - Original Message - From: William Silvert cien...@silvert.org To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Tuesday, May 11, 2010 7:31 AM Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Although Jim Crants in a later post raised questions about whether by being fuzzy we risk avoiding responsible for human actions, I have to take issue with Roper's definitions. In large part this is because in some cases the distinction between humans and (other) animals is not relevant. Clearly in cases like the introduction of the rabbit to Australia we have a clear case of introduction, 100% in fuzzy terms. But consider the following cases: When American Bison migrate they disperse parasites and disease organisms, clearly this is a natural process. When Bison are depleted due to human depredation they may travel in search of mates, again dispersing parasites and disease organisms. Indians used to stampede Bison over cliffs as a means of hunting them, the survivors may flee and disperse parasites and disease organisms. Cattle grazing in the lands where Bison used to be plentiful may disperse parasites and disease organisms in the same way. Human herders following the cattle may disperse parasites and disease organisms on their clothing. And so on. Are nomadic tribes totally different from migrating animals? Crants later writes that Invasive species biology loses most of its social relevance if native and exotic species are not ecologically distinguishable. but I do not think that we need to draw sharp lines between them. Migrations can be blocked by fences and roads, nomads may be confined within national boundaries. I don't think that invasive species biology requires that every species be either totally invasive or totally natural. And imagine what would happen if some exotic species that we blamed on ballast water transport turned out to arrive via a parasitic life stage on some migratory fish! All those papers to be withdrawn! One of the greatest invasions in ecological history occurred when the Mediterranean connected to the Atlantic Ocean. How fundamentally different is that from the opening of the Suez or Panama canals? Bill Silvert - Original Message - From: James J. Roper jjro...@gmail.com To: ECOLOG-L@LISTSERV.UMD.EDU Sent: segunda-feira, 10 de Maio de 2010 22:52 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. James Crants wrote on 10-May-10 12:51: In the discussion off-forum, we were unable to come to any conclusions because we could not agree on answer to even the most fundamental question: is the distinction between exotic and native species ecologically meaningful? If you can't agree on that, there's no point in going on to ask whether there's such a thing as an invasive exotic species, whethere invasive exotics are a problem, and what, if anything, we should do about it. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.437 / Virus Database: 271.1.1/2866 - Release Date: 05/10/10 18:26:00
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
James Crants wrote on 11-May-10 13:05: There's a difference between saying that two species are not ecologically equivalent and saying that two categories of species are not ecologically equivalent. But, ecological equivalents are not really equal in such a way that they are substitutable in a community. I mean, you can't just say, take a Clay-colored Robin from Panama and replace the American Robin (even though they might be considered ecological equivalents) and then expect their roles to just fit right in in their new places. If exotic species (as a category) were ecologically equivalent to native ones, you would still find that every species would differ from every other species by at least a few measures. I'm saying that, as a category, exotic species are ecologically different from native ones. Now do you mean until they are naturalized? After all, take the House Sparrow, that has now crossed the continent and invaded many places in the Americas. Is it still ecologically different from natives? I would suggest that if you took both native and introduced species, and did a blind study, in which you looked at survival, interactions and so on, you would not get a clear cut difference in ecological characters that would identify (say, through a discriminant function analysis) introduced and native species. Take the persimmons I have here in my yard here in southern Brazil. Clearly introduced from Japan (I will eliminate them once I have a native fruit tree to replace them with), but they attract leaf-cutter ants to consume leaves, bees and other insects visit the flowers, all kinds of animals eat the fruits, and they seeds are quite viable and the plant could easily become invasive and probably is in many places. If you took a native plant here, like the Scheflera (Didymopanax) and checked it out, you would find that, as a sapling, it cannot handle our cold winters (frost burns every year), it gets hit by aphids so badly that it is often worse than the frost, and the leaf cutter ants also nail it. In the same time my one native sapling has remained at the same size (short, 1 m tall), a persimmon has grown from a seed and is now producing fruit and is about 3 m tall. The Scheflera is at least 9 years old, while the persimmon is about 3. I would suggest that through any objective measurements by a naive observer, they would think that the Scheflera was NOT native and that the Persimmon was. So, my point is, that using objective measurements, I think we would not find that there are clear distrinctions between native and introduced organisms. We may find certain kinds of trends, but the errors associated with using those trends as guides to recognize native or introduced organisms will be large and so not very useful. Cheers, Jim
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jason, There are few things qualitatively different about any dispersal agent. But, considering the impact and abundance of humans and their dispersal agents these days, there is a quantitative difference. Also, there is a qualitative difference at least in one respect. Dispersal is an evolved trait (at least modified by evolution) while human-mediated dispersal can disperse organisms that did not evolve to be good dispersers. Thus, between the quantitative difference (increased dispersal rates, greater dispersal distances due to humans) and the qualitative difference (dispersal of comparatively poor dispersers due to humans), the combined effects ONLY means a greater rate of introductions, often of species that would never have dispersed by any other means, than ever in the history of the planet. But, besides that, there is no difference between dispersal agents and events. Cheers, Jim Jason Hernandez wrote on 11-May-10 21:48: What, then, is the ecological difference between humans as a dispersal agent, and, say, seabirds as a dispersal agent? When we study Hawaiian native plants, are we not studying how natural selection influenced organisms after their introduction, or as a consequence of the introduction of other species? The system is still one of an organism having been brought to some isolated location to which it could not otherwise have gotten on its own. The whole study of island biodiversity is inherently the study of introductions of alien species by various means, except in the case of continental islands formerly connected to the mainland. Jason Hernandez East Carolina University
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Humans are not part of nature? No wonder the planet is sick. On Tue, May 11, 2010 at 10:15 PM, Geoffrey Patton gwpatt...@yahoo.comwrote: This has been an especially interesting and worthwhile discussion, particularly on the ethics front. My ethics derive from an ecologist whose name I can no longer recall but whose mantra was that Nature took millions of years to sort out the current state and any human-caused change is, by definition, adverse. Where people have a hand in it, it is bad, regardless of any perceived shot-term benefit. Pedagogical but true in my view. Cordially yours, Geoff Patton, Ph.D. 2208 Parker Ave., Wheaton, MD 20902 301.221.9536 --- On Tue, 5/11/10, James Crants jcra...@gmail.com wrote: From: James Crants jcra...@gmail.com Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To: ECOLOG-L@LISTSERV.UMD.EDU Date: Tuesday, May 11, 2010, 10:47 AM I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more prone to failure than those where any and all ecological outcomes are deemed acceptable, but that's only because failure in the former group means invasion and domination by exotic species, while there is no such thing as failure in the latter group. JC(2) Very-long-distance dispersal by humans confers a fitness advantage over very-long-distance dispersal by other agents, on average, for two reasons. First, humans often disperse organisms in groups, such as containers of seeds, shipments of mature plants and animals, or large populations contained in ballast water, allowing them to overcome the Allee effects (lack of mates, inbreeding depression) their populations would face if introduced as one or a few individuals. We also often take pains to maximize the establishment success of organisms we disperse, by shipping healthy, mature plants and animals and propogating them when they arrive, while non-human dispersal agents usually introduce small numbers of organisms, often nowhere near their peak fitness potential (e.g
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jim and others, Your last sentence converges on the point I was trying to make: if you compared native species, as a group, against exotic species, as a group, you would find statistically significant ecological differences (ie, trends), even though you would also find numerous exceptions to those trends. A statistically significant trend is not negated by the existence of outliers, any more than the tendency for men to be taller than women is negated by the fact that many women are taller than many men. Trends are important. Trends are objectively identifiable patterns, and scientific conclusions can only be drawn based on objectively identifiable patterns. If you focus on just one or a few data points, selected so as to seem to either support or contradict a hypothesized trend, you aren't doing science; you're just telling stories (and cherrypicking your data). Stories can be OK for illustrating a point (ie, giving an example), as they can sometimes convey an idea better than trendlines can, but you can't draw scientific conclusions from a story or two. Mark Dixon correctly predicts that there are recent meta-analyses that are relevant to our discussion. I downloaded a few a couple weeks ago, but I've spent too much time writing arguments to spare any for looking at the actual evidence. Here's a relevant-sounding, recent review to look into, if anyone's interested: van Kleunen et al. (2010). A meta-analysis of trait differences between invasive and non-invasive plant species. Ecology Letters 13(2): 235-245. This and other useful-looking papers pop up if you search ISI Web of Knowledge for exotic native ecology and refine the search to include only reviews. Adding the word community refines things further, though I'm not sure it doesn't exclued some relevant papers. I should try to clarify again why I'm focused on the ecological differences between exotic and native species. The idea that we should control invasive species is a moral position (as is any position on a question of what people should do). One attack against this position is as follows: (1) there is no ecological difference between exotic and native species, so favoring one over the other is completely arbitrary, and (2) even if there were a difference, there is nothing morally good about favoring one over the other. The second part of this attack is itself a moral position, and is therefore not within the realm of things that can be settled by purely rational debate. At any rate, I think it only becomes important if the first point can be effectively countered. If ecological invasion by exotic species has no ecological consequences, I have trouble seeing why it's so important to control exotic invasive species. Fortunately, that first point can be debated rationally, on the evidence. Most of what I've been trying to say here, then, revolves around making the general case that we should expect exotic species invasions to be ecologically consequential, and I've been trying to provide a few examples of ecological differences I would expect to find between exotic and native species, based on what I can remember from various classes, papers, and conversations over many years. Similarly, if human-mediated dispersal is ecologically indistinguishable from dispersal by any other agent, that would seem to undermine the case for trying to regulate human-mediated dispersal. If, on the other hand, we differ substantially from other dispersal agents, and if we can control our own efficiency as dispersal agents, AND if introducing exotic species to ecosystems has ecological consequences, we can then ask the moral question of whether we *should* control our efficiency as dispersal agents. On the question of whether humans are separate from nature, I just want to re-emphasize that there are positives and negatives to either view. If we say we are separate from nature, we recognize that we are very different from other species in important ways. The up-side is that we recognize our power to change things and make predictions about what the outcomes of our actions will be, so we don't have to go around blindly mucking things up for everything else in our ecosystem if we don't want to. The down-side of having the power to avoid blindly mucking things up is that we've often used it to go around *deliberately* mucking things up. We have tended to consider our actions only in terms of their short-term effects on our own species, with nature divided into those things we can use and those things that are in our way. The costs and benefits to considering ourselves part of nature are just the reverse: it makes it more likely that we will consider other parts of the ecosystem in our planning, but it allows us to rationalize that anything we do is just as natural as anything any other organism does, so the question of how we affect the rest of the ecosystem is rendered morally neutral. However you look at it, humans can find
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
So, Mr. Patton, if you could, would you re-introduce smallpox and polio? It took nature millions of years to get them working properly on the human population. Martin Meiss 2010/5/12 Jan Ygberg jygb...@gmail.com Humans are not part of nature? No wonder the planet is sick. On Tue, May 11, 2010 at 10:15 PM, Geoffrey Patton gwpatt...@yahoo.com wrote: This has been an especially interesting and worthwhile discussion, particularly on the ethics front. My ethics derive from an ecologist whose name I can no longer recall but whose mantra was that Nature took millions of years to sort out the current state and any human-caused change is, by definition, adverse. Where people have a hand in it, it is bad, regardless of any perceived shot-term benefit. Pedagogical but true in my view. Cordially yours, Geoff Patton, Ph.D. 2208 Parker Ave., Wheaton, MD 20902 301.221.9536 --- On Tue, 5/11/10, James Crants jcra...@gmail.com wrote: From: James Crants jcra...@gmail.com Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To: ECOLOG-L@LISTSERV.UMD.EDU Date: Tuesday, May 11, 2010, 10:47 AM I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more prone to failure than those where any and all ecological outcomes are deemed acceptable, but that's only because failure in the former group means invasion and domination by exotic species, while there is no such thing as failure in the latter group. JC(2) Very-long-distance dispersal by humans confers a fitness advantage over very-long-distance dispersal by other agents, on average, for two reasons. First, humans often disperse organisms in groups, such as containers of seeds, shipments of mature plants and animals, or large populations contained in ballast water, allowing them to overcome the Allee effects (lack of mates, inbreeding depression) their populations would face if introduced as one
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jim, I hope my (perhaps) subtle tongue in cheek comments about invasives has not confused the issue. I completely agree that human caused introductions are to be avoided at all costs, and active eradication of exotics should be undertaken as a default position until a well-developed argument suggests otherwise. As Elton documented long ago, invasives are problems, both ecologically and financially. States and countries spends billions of dollars each year trying to control many exotics. While I think that we can find examples for both, innocuous exotics and maladapted natives, those examples do not support any position taken on exotics. I would also venture to state that even if statistical tests could not identify an exotic, that does NOT mean the exotic is inconsequential. I think in this case, we should assume guilty until proven innocent. After all, nature took millions of years to come up with what we have today, while we can screw that up in less than a decade. We do not have the information required to decide whether an exotic matters in some philosophical moral sense. We should assume that it is a problem, however, as the best default position - avoid introductions at all costs, eradicate when possible. If we use a moral position, that position can be argued endlessly. If we use a pragmatic position - introductions are uncontrolled experiments and uncontrolled experiments should always be avoided because we cannot know how to predict the outcome (and much less control it) - then until someone can really show how great uncontolled experiments are, no argument will be effective against it. Sincerely, Jim James Crants wrote on 12-May-10 13:02: Jim and others, Your last sentence converges on the point I was trying to make: if you compared native species, as a group, against exotic species, as a group, you would find statistically significant ecological differences (ie, trends), even though you would also find numerous exceptions to those trends. A statistically significant trend is not negated by the existence of outliers, any more than the tendency for men to be taller than women is negated by the fact that many women are taller than many men.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Humans were part of Nature, before they developed a kind of psychopathology (something like obsessive-compulsive disorder?) in which their focus shifted from survival to acquisition far beyond survival--even to the truly insane state where the very tools they invented to survive are now the major threats to their survival and that of many other organisms. That, I suspect, is the crucial tipping point where Nature and Culture came into opposition. Among the consequences of that trend, unique among organisms, lie the phenomena of invasive organisms--in varying degrees of intensity of effect, but nonetheless different. Humans are, of course, still part of Nature, only less so as a result of the advent of culture and civilization. WT - Original Message - From: Jan Ygberg jygb...@gmail.com To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Wednesday, May 12, 2010 7:16 AM Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Humans are not part of nature? No wonder the planet is sick. On Tue, May 11, 2010 at 10:15 PM, Geoffrey Patton gwpatt...@yahoo.comwrote: This has been an especially interesting and worthwhile discussion, particularly on the ethics front. My ethics derive from an ecologist whose name I can no longer recall but whose mantra was that Nature took millions of years to sort out the current state and any human-caused change is, by definition, adverse. Where people have a hand in it, it is bad, regardless of any perceived shot-term benefit. Pedagogical but true in my view. Cordially yours, Geoff Patton, Ph.D. 2208 Parker Ave., Wheaton, MD 20902 301.221.9536 --- On Tue, 5/11/10, James Crants jcra...@gmail.com wrote: From: James Crants jcra...@gmail.com Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To: ECOLOG-L@LISTSERV.UMD.EDU Date: Tuesday, May 11, 2010, 10:47 AM I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more prone to failure than those where any and all ecological outcomes are deemed acceptable, but that's only because
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Really, Mr. Roper (the formality is to avoid confusion between the two Jims)? You would favor removal of such exotics from North America as wheat, apples, oranges, horses, cattle, goats, pigs, and honeybees? Wouldn't you settle for trying to keep them from running wild, rather than eliminating them from farmland because they are exotic? Martin 2010/5/12 James J. Roper jjro...@gmail.com Jim, I hope my (perhaps) subtle tongue in cheek comments about invasives has not confused the issue. I completely agree that human caused introductions are to be avoided at all costs, and active eradication of exotics should be undertaken as a default position until a well-developed argument suggests otherwise. As Elton documented long ago, invasives are problems, both ecologically and financially. States and countries spends billions of dollars each year trying to control many exotics. While I think that we can find examples for both, innocuous exotics and maladapted natives, those examples do not support any position taken on exotics. I would also venture to state that even if statistical tests could not identify an exotic, that does NOT mean the exotic is inconsequential. I think in this case, we should assume guilty until proven innocent. After all, nature took millions of years to come up with what we have today, while we can screw that up in less than a decade. We do not have the information required to decide whether an exotic matters in some philosophical moral sense. We should assume that it is a problem, however, as the best default position - avoid introductions at all costs, eradicate when possible. If we use a moral position, that position can be argued endlessly. If we use a pragmatic position - introductions are uncontrolled experiments and uncontrolled experiments should always be avoided because we cannot know how to predict the outcome (and much less control it) - then until someone can really show how great uncontolled experiments are, no argument will be effective against it. Sincerely, Jim James Crants wrote on 12-May-10 13:02: Jim and others, Your last sentence converges on the point I was trying to make: if you compared native species, as a group, against exotic species, as a group, you would find statistically significant ecological differences (ie, trends), even though you would also find numerous exceptions to those trends. A statistically significant trend is not negated by the existence of outliers, any more than the tendency for men to be taller than women is negated by the fact that many women are taller than many men.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Of course. And malarial mosquitoes and guinea worm and all those other well evolved creatures. Nature is not good, Nature is neutral. What is natural is what works. Nature is like a businessman who is only concerned about making money, he may do good by creating jobs and producing products that people want, but he may also get rich by manufacturing flamable baby clothes and other undesirable things. Just because Nature took a long time getting us where we are today does not mean that the current natural state is the best of all possible worlds. Bill Silvert - Original Message - From: Martin Meiss mme...@gmail.com To: ECOLOG-L@LISTSERV.UMD.EDU Sent: quarta-feira, 12 de Maio de 2010 17:17 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc So, Mr. Patton, if you could, would you re-introduce smallpox and polio? It took nature millions of years to get them working properly on the human population. Martin Meiss 2010/5/12 Jan Ygberg jygb...@gmail.com Humans are not part of nature? No wonder the planet is sick. On Tue, May 11, 2010 at 10:15 PM, Geoffrey Patton gwpatt...@yahoo.com wrote: This has been an especially interesting and worthwhile discussion, particularly on the ethics front. My ethics derive from an ecologist whose name I can no longer recall but whose mantra was that Nature took millions of years to sort out the current state and any human-caused change is, by definition, adverse. Where people have a hand in it, it is bad, regardless of any perceived shot-term benefit. Pedagogical but true in my view. Cordially yours, Geoff Patton, Ph.D. 2208 Parker Ave., Wheaton, MD 20902 301.221.9536 --- On Tue, 5/11/10, James Crants jcra...@gmail.com wrote: From: James Crants jcra...@gmail.com Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To: ECOLOG-L@LISTSERV.UMD.EDU Date: Tuesday, May 11, 2010, 10:47 AM I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Humans are not the only animals which have destr4uctive compulsions. Young elephants like to test their strength by knocking down trees -- they don't do anything with them, they just destroy for the pleasure of it. Quite a strange sight to see! I suspect that there are other animals which act in ways that have no obvious benefit but which meet destructive psychological needs. Bill Silvert - Original Message - From: Wayne Tyson landr...@cox.net To: ECOLOG-L@LISTSERV.UMD.EDU Sent: quarta-feira, 12 de Maio de 2010 21:00 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Humans were part of Nature, before they developed a kind of psychopathology (something like obsessive-compulsive disorder?) in which their focus shifted from survival to acquisition far beyond survival--even to the truly insane state where the very tools they invented to survive are now the major threats to their survival and that of many other organisms. That, I suspect, is the crucial tipping point where Nature and Culture came into opposition. Among the consequences of that trend, unique among organisms, lie the phenomena of invasive organisms--in varying degrees of intensity of effect, but nonetheless different. Humans are, of course, still part of Nature, only less so as a result of the advent of culture and civilization.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Good question Martin, But, yes, I would remove all of those from any and all natural settings, and keep them on farms, just like you suggested. As for the animals, they are massive conservation problems in their own rights, so I won't go into why we should all be vegetarian - :-| As you say, keep them from running wild. Which reminds me, have any of you seen those pictures of the record sized boars (domestic pigs) that were shot in Georgia a few years ago? Those are certainly an ecological disaster! Cheers, Jim On Wed, May 12, 2010 at 13:57, Martin Meiss mme...@gmail.com wrote: Really, Mr. Roper (the formality is to avoid confusion between the two Jims)? You would favor removal of such exotics from North America as wheat, apples, oranges, horses, cattle, goats, pigs, and honeybees? Wouldn't you settle for trying to keep them from running wild, rather than eliminating them from farmland because they are exotic? Martin 2010/5/12 James J. Roper jjro...@gmail.com Jim, I hope my (perhaps) subtle tongue in cheek comments about invasives has not confused the issue. I completely agree that human caused introductions are to be avoided at all costs, and active eradication of exotics should be undertaken as a default position until a well-developed argument suggests otherwise. As Elton documented long ago, invasives are problems, both ecologically and financially. States and countries spends billions of dollars each year trying to control many exotics. While I think that we can find examples for both, innocuous exotics and maladapted natives, those examples do not support any position taken on exotics. I would also venture to state that even if statistical tests could not identify an exotic, that does NOT mean the exotic is inconsequential. I think in this case, we should assume guilty until proven innocent. After all, nature took millions of years to come up with what we have today, while we can screw that up in less than a decade. We do not have the information required to decide whether an exotic matters in some philosophical moral sense. We should assume that it is a problem, however, as the best default position - avoid introductions at all costs, eradicate when possible. If we use a moral position, that position can be argued endlessly. If we use a pragmatic position - introductions are uncontrolled experiments and uncontrolled experiments should always be avoided because we cannot know how to predict the outcome (and much less control it) - then until someone can really show how great uncontolled experiments are, no argument will be effective against it. Sincerely, Jim James Crants wrote on 12-May-10 13:02: Jim and others, Your last sentence converges on the point I was trying to make: if you compared native species, as a group, against exotic species, as a group, you would find statistically significant ecological differences (ie, trends), even though you would also find numerous exceptions to those trends. A statistically significant trend is not negated by the existence of outliers, any more than the tendency for men to be taller than women is negated by the fact that many women are taller than many men.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jim, you raise a good point (or more) about the kinds of arguments that work. The problem with moral arguments is that they are so nebulous and subjective that they will never defeat a person who just doesn't want to change. I can think of many examples, but none seems to be politically correct to comment on here, so I will leave that up to imagination. I will summarize by saying any moral position can have a contrary moral position that is just as morally valid. However, moral positions are indeed what motivate many people. On the other hand, logical positions (contrasting strongly when the two may not always be at odds) stand on the strength of the logic and can be difficult to refute if one accepts the premises. What we all need to recognize is when we argue, which kind of person are we arguing with - one that will accept our moral stance and agree with us (after all, if they don't, we lost the argument) or one that will accept our premises and yield to logic. The general public often comprises people that mix the two - and they don't recognize when they cross logic and moral boundaries - hence our task is that much more difficult. Cheers, Jim On Wed, May 12, 2010 at 16:28, James Crants jcra...@gmail.com wrote: Jim, Yes, any tongue-in-cheek comments flew right over my head, so I was taking everything in earnest. I should have realized from your earlier references to Elton that you at least recognized exotic invasives as an ecological problem. I think I've sown my own bit of confusion by arguing that exotics are ecologically different from natives. Not only might it not matter, as you suggest, but by phrasing my point in terms of exotics versus natives, I've probably given the impression that I'm just as worked up about wheat, cows, and dandelions as I am about buckthorn, earthworms, and purple loosestrife (to give some examples from my own region, Minnesota, USA). I probably shouldn't be surprised if people think my views on the matter are more rigid and compartmentalized than they really are. You may be right that it is logically better to argue that we shouldn't be conducting unnecessary experiments with unknown outcomes, rather than making moral appeals. Personally, I think both kinds of arguments (rational and moral) are needed. People can be persuaded by reason, but they aren't often strongly motivated by it. We need reason to understand the likely outcomes of different possible courses of action, and appeals to human values to get people to care about those outcomes. With moral arguments alone, though, I agree that the argument just goes on indefinitely, with neither side ever feeling compelled to admit defeat. Unfortunately, the loudest side wins moral debates, and that seems never to be the side I'm on. Jim
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Hi Jim et al., I guess I don't undertand what one would mean by your question, as to whether they behave differently. No two species behave the same in any event, so any given pair of species behaves differently, regardless of origin. Have you read Ricklefs - Disintegration of the ecological community? If the community is more of an accident in space and time rather than a co-evolved bunch of species, then there is no reason to think that any two species behave the same. Let's put it in terms of testable hypotheses. Let's say we have two species, A and B, both are native and we have C, non native. Hypothesis: (A = B) ne C? (where ne is not equal). Clearly A ne B ne C, because, they are all different species. If you can put your idea of behavior being equal in terms of testable hypotheses, I think we could advance. I would also like to see the word matter as in does it matter? placed into a real context, with hypotheses included. I still think the ambiguity of the terms is the reason behind the confusion. Cheers, Jim James Crants wrote on 10-May-10 19:23: Jim, Actually, you answered the question of whether exotic and native species can be distinguished at all, while the question we could not agree on is whether the distinction is ecologically meaningful. Does an exotic species behave differently from a native one? If not, then why should it matter to an ecologist whether a species is native or not? I say exotic species do behave differently, for reasons I gave in my post, and I think it does matter whether a species is native. Dr. Chew (as I understand it) says exotic species do not behave differently, as a group, that the distinction is ecologically meaningless, and that it therefore does not matter whether a species is native. We define native and exotic based on geographic history, and I think he says that that's the only distinction that can objectively be made between the two categories. I would agree with William Silvert that we are getting wrapped up in irrelevant rigor, except that I think important things might hang in the balance here. Invasive species biology loses most of its social relevance if native and exotic species are not ecologically distinguishable. Also, while I agree that we have to accept fuzzy definitions for fuzzy concepts (i.e., most concepts), a tendency emerged in the off-forum discussion to fuzz everything together to the point where humans are just another organism, nothing we do is exceptional, and we have no moral obligation to modify our ecological impact, one way or another, even if doing so is well within our power. That's a matter of using such fuzzy definitions that they cease to be definitions at all, which is different from what Silvert is advocating, but I guess I'm just saying that it's important not to throw out a categorization just because the categories have fuzzy boundaries. Jim Crants On Mon, May 10, 2010 at 4:52 PM, James J. Roper jjro...@gmail.com mailto:jjro...@gmail.com wrote: Ah Jim, But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. Clearly this is a mere consequence of the short history of humans as dispersal agents on the planet, but it is a good enough definition for 99% of the cases - just check the classic by Elton. We already have the term naturalized which basically means it's here to stay and there is nothing we can do about it. I personally think that for almost all intents and purposes, those definitions work. When they don't work, we are either splitting hairs or don't have clear objectives. I think a clear consequence of this, is that humans should avoid introducing and we should often actively eliminate introductions. But, that idea is based on the premise that we want nature to run its course without human help - but that is not a universally accepted premise. And, a second premise is that evolution by natural selection and how nature may have influenced that through genetic drift, lateral gene transfer or what have you, is what is interesting about nature. I can see a future in which ecologists merely study how natural selection influenced organisms after their introduction, or as a consequence of the introduction of other species. Boring. After all, those will always be on a short term scale and will only illustrate what we probably already know about evolution. The big picture, long term consequence of continental drift, punctuated equilibrium and so on, which have resulted in the fascinating diversity of life, do not occur in one or two human generations - but we can certainly wipe out the evidence of them in the same short time frame. Extinctions and introduced species will do just
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jim misses my point. The difference is not whether we call the transfers natural or anthropogenic, but whether we can control them. I think that we need to focus on what we can do about transfers and not get tied up in trying to define natural and invasive. After all, we can also control some natural events. Bill - Original Message - From: James J. Roper jjro...@gmail.com To: William Silvert cien...@silvert.org Cc: ECOLOG-L@LISTSERV.UMD.EDU Sent: terça-feira, 11 de Maio de 2010 15:45 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc To go straight to the meat of the issue: William Silvert wrote on 11-May-10 11:31: One of the greatest invasions in ecological history occurred when the Mediterranean connected to the Atlantic Ocean. How fundamentally different is that from the opening of the Suez or Panama canals? Well, sure, but trivially so. We are only talking about rates here. And, the fact that we will lose diversity and richness and local history as a consequence of our introductions. But, over geological time, it's just a drop in the bucket. Indeed, your argument, taken to its extreme is, well, since the big bang, all kinds of things have happened and until the big freeze they will continue, so why does it matter what happens in our lifetimes? Clearly we need to define the word matter as in what does it matter. Cheers, Jim
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
The translocation of species around the world can, and do, have dramatic effects on the world's ecosystems. Well known and respected ecologists rank these biological exchanges as one of leading threats to ecosystem integrity in marine, freshwater, and terrestrial ecosystems over the next 100 years (see Sala et al. 2000, Simberloff 1996, and others). These rankings are in part a matter of conjecture, but we also have a great body of quantitative knowledge on the effects of biological exchanges. When we ask the question 'Are non-native species ecologically different from native species?' we must be careful not to lose ourselves in semantics. This said, there is legitimate concern among ecologists regarding the development of a sub-field of invasion biology that operates in isolation from other ecological disciplines such as community ecology. Simply put, non-native species may have very similar ecological functions from native species and lessons learned in community ecology should help drive our understanding of biological invasions. Does this mean there is not a meaningful ecological distinction? Absolutely not. When species are moved around and between continents by human activities (at increasingly high rates) they often leave behind natural predators, competitors, parasites, and diseases. In some cases these non-native species become troublesome, and in a small proportion of cases very troublesome. Thus, from a community ecology perspective non-native species that may be functionally similar to native species may still induce changes in food webs, nutrient cycling, etc that have far reaching implications. So, are exotic and native species ecologically different...they certainly can be. Is the distinction ecologically meaningful...absolutely. Scott Higgins -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ecolo...@listserv.umd.edu] On Behalf Of James Crants Sent: Monday, May 10, 2010 5:23 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Jim, Actually, you answered the question of whether exotic and native species can be distinguished at all, while the question we could not agree on is whether the distinction is ecologically meaningful. Does an exotic species behave differently from a native one? If not, then why should it matter to an ecologist whether a species is native or not? I say exotic species do behave differently, for reasons I gave in my post, and I think it does matter whether a species is native. Dr. Chew (as I understand it) says exotic species do not behave differently, as a group, that the distinction is ecologically meaningless, and that it therefore does not matter whether a species is native. We define native and exotic based on geographic history, and I think he says that that's the only distinction that can objectively be made between the two categories. I would agree with William Silvert that we are getting wrapped up in irrelevant rigor, except that I think important things might hang in the balance here. Invasive species biology loses most of its social relevance if native and exotic species are not ecologically distinguishable. Also, while I agree that we have to accept fuzzy definitions for fuzzy concepts (i.e., most concepts), a tendency emerged in the off-forum discussion to fuzz everything together to the point where humans are just another organism, nothing we do is exceptional, and we have no moral obligation to modify our ecological impact, one way or another, even if doing so is well within our power. That's a matter of using such fuzzy definitions that they cease to be definitions at all, which is different from what Silvert is advocating, but I guess I'm just saying that it's important not to throw out a categorization just because the categories have fuzzy boundaries. Jim Crants On Mon, May 10, 2010 at 4:52 PM, James J. Roper jjro...@gmail.com wrote: Ah Jim, But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. Clearly this is a mere consequence of the short history of humans as dispersal agents on the planet, but it is a good enough definition for 99% of the cases - just check the classic by Elton. We already have the term naturalized which basically means it's here to stay and there is nothing we can do about it. I personally think that for almost all intents and purposes, those definitions work. When they don't work, we are either splitting hairs or don't have clear objectives. I think a clear consequence of this, is that humans should avoid introducing and we should often actively eliminate introductions. But, that idea is based on the premise that we want nature to run its course without human help - but that is not a universally accepted premise
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
I think I have not made my arguments clearly enough. I merely intended to summarize my moral case for suppressing invasives as part of my summary of the off-forum conversation. My numbered paragraphs were intended to address the claim that there is no ecological difference between native and exotic species, and the claim that there is no ecological difference between human-mediated dispersal and dispersal by any other agent. My responses to Matt's responses to those paragraphs are below: JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC (1b) The argument about how many species interact with fewer species than average misses my point. I'm saying that, if you counted the biological interactions for each native species and each exotic species in some area (could be a square meter, could be the world), I believe you would find that the average number for exotic species would be significantly lower than the average for exotic species. Thus, exotic species are ecologically different from native species. Actually, having more interactions may mean greater stability, on average, since some of those interactions are functionally redundant. I would have to brush up on my community ecology to be sure I'm not being overly simplistic, but I know this is true in pollination systems; pollinators that interact with more angiosperm species have greater population stability, on average, and angiosperms with more pollinator species have greater reproductive stability, on average (though I don't know if this leads to greater population stability for long-lived species). I'm not sure what you mean by systems with a higher likelihood of failure. It seems to me that failure is a matter of human values not being realized. If, by failure, you mean rapid change, well, that hardly seems to be a problem for you. I would have to agree that systems managed to promote natives at the expense of exotics are more prone to failure than those where any and all ecological outcomes are deemed acceptable, but that's only because failure in the former group means invasion and domination by exotic species, while there is no such thing as failure in the latter group. JC(2) Very-long-distance dispersal by humans confers a fitness advantage over very-long-distance dispersal by other agents, on average, for two reasons. First, humans often disperse organisms in groups, such as containers of seeds, shipments of mature plants and animals, or large populations contained in ballast water, allowing them to overcome the Allee effects (lack of mates, inbreeding depression) their populations would face if introduced as one or a few individuals. We also often take pains to maximize the establishment success of organisms we disperse, by shipping healthy, mature plants and animals and propogating them when they arrive, while non-human dispersal agents usually introduce small numbers of organisms, often nowhere near their peak fitness potential (e.g., seeds, spores, starving and dehydrated animals). MC(2). JC appears to be arguing that once rare occurrences are no longer rare. I agree. But I draw the opposite conclusion, because he is arguing that to generate such changes is morally wrong, while I am just saying: when these conditions prevail, long distance dispersal becomes normal. JC(2b) I'm not saying anything (here) about whether the recent commonness of previously-rare dispersal events is morally wrong. I'm countering the argument that human-mediated dispersal confers no fitness advantage over dispersal by any other agent. Others may be aware of an invasive exotic species that was not imported by humans in far greater numbers than we could reasonably expect from any other agent, even if it had 100,000 years to work, but I am not. Furthermore, most invasive species were carefully planted and tended across large areas. Others may know of a dispersal agent that takes such care of the species it disperses AND has any realistic potential
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Jim Roper, There's a difference between saying that two species are not ecologically equivalent and saying that two categories of species are not ecologically equivalent. If exotic species (as a category) were ecologically equivalent to native ones, you would still find that every species would differ from every other species by at least a few measures. I'm saying that, as a category, exotic species are ecologically different from native ones. I am deliberately leaving this difference vague because the term ecologically different can serve as an umbrella for all kinds of differences that are relevant to interactions among organisms and between organisms and their environment. Specific differences I would expect to find include: (1) exotic plants have fewer insect herbivore species and lose a smaller percentage of their biomass to insect herbivores than native plants, and (2) exotic species have fewer pathogens than native species. Similarly, I am using vague terms like behave and matters because I want to include a wide array of phenomena, though I suppose you could reasonably argue against the idea of species behaving on the grounds that behavior is something individual organisms or closely connected groups of individuals do. I think most of the confusion in this conversation comes from the fact that Matthew Chew and I just don't agree on whether there's any ecological difference between exotic species and native ones. If they aren't, then what's the point in investing time, money, and energy in controlling exotic species or propagating natives? William Silvert, I didn't really mean to disagree with your fuzzy definitions. In fact, I like them, and I think you could get some ecological insights by using those definitions that you could miss with artificially clear distinctions. Also, I've said more than once that, if we have to throw out any term with indistinct boundaries, we won't find we have much at all left to discuss in the field of ecology. We would not be able to talk about forests, pollinators, the Mediterranean Sea, etc. I just wanted to emphasize, in anticipation of certain everything's the same as everything else arguments that have come up before, that there's a difference between categories with fuzzy boundaries and categories that are totally indistinct and therefore meaningless. One of the keys to arguing against controlling invasive exotic species is destroying the moral arguments that motivate people to bother in the first place. To do this, it helps to use clever language to blur the lines between categories to the point where it's hard to see that native, exotic, invasive, and non-invasive have any meaning at all, except as inflammatory terms used by people who want to manipulate your emotions. The same basic approach is used to stop people doing anything about global warming (e.g., the globe warms and cools all the time; without global warming, earth would be frozen and hostile to life; why do we get excited about human CO2 emissions and not volcanic ones?), species extinctions (repeat the above, modifying appropriately), deforestation (repeat), and so on. For that matter, blurring the lines between humans and everything else (humans are part of nature) is very effective. For one thing, humans ARE a part of nature, and we do cause some harm by saying we're not. For another, it's easy to reduce this down to humans are just another animal, thus ignoring our truly exceptional intellectual abilities and capacity for empathy and moral thought. Anyway, I wanted to head off these sorts of defitions-so-fuzzy-they-mean-nothing, not to disagree with the definitions you gave. As for oceans merging, I can't see a big ecological distinction between the Mediterranean joining the Alantic without human intervention and humans building the Suez and Panama Canals. If anything, I bet the Mediterranean-Atlantic merger was more ecologically dramatic than the canals, in that it probably changed the sea level and salinity of the Mediterranean quite a bit, and the migration of species into the Mediterranean was probably more rapid. Also, it can hardly be argued that two oceanic mergers via human-made canal within a century is a rapidly greater rate of mergers than one merger without human intervention in the same amount of time. All my arguments about humans bringing more species in greater numbers than other dispersal agents, and tending them more carefully after dispersal, do not apply to these cases, as far as I know. Jim Crants
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
C'mon, Bill S, It sounds like you're advocating rational policy based on case-by-case evaluation with regard to consensus values. Where ya gonna get with that? Martin Meiss 2010/5/11 William Silvert cien...@silvert.org Although Jim Crants in a later post raised questions about whether by being fuzzy we risk avoiding responsible for human actions, I have to take issue with Roper's definitions. In large part this is because in some cases the distinction between humans and (other) animals is not relevant. Clearly in cases like the introduction of the rabbit to Australia we have a clear case of introduction, 100% in fuzzy terms. But consider the following cases: When American Bison migrate they disperse parasites and disease organisms, clearly this is a natural process. When Bison are depleted due to human depredation they may travel in search of mates, again dispersing parasites and disease organisms. Indians used to stampede Bison over cliffs as a means of hunting them, the survivors may flee and disperse parasites and disease organisms. Cattle grazing in the lands where Bison used to be plentiful may disperse parasites and disease organisms in the same way. Human herders following the cattle may disperse parasites and disease organisms on their clothing. And so on. Are nomadic tribes totally different from migrating animals? Crants later writes that Invasive species biology loses most of its social relevance if native and exotic species are not ecologically distinguishable. but I do not think that we need to draw sharp lines between them. Migrations can be blocked by fences and roads, nomads may be confined within national boundaries. I don't think that invasive species biology requires that every species be either totally invasive or totally natural. And imagine what would happen if some exotic species that we blamed on ballast water transport turned out to arrive via a parasitic life stage on some migratory fish! All those papers to be withdrawn! One of the greatest invasions in ecological history occurred when the Mediterranean connected to the Atlantic Ocean. How fundamentally different is that from the opening of the Suez or Panama canals? Bill Silvert - Original Message - From: James J. Roper jjro...@gmail.com To: ECOLOG-L@LISTSERV.UMD.EDU Sent: segunda-feira, 10 de Maio de 2010 22:52 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. James Crants wrote on 10-May-10 12:51: In the discussion off-forum, we were unable to come to any conclusions because we could not agree on answer to even the most fundamental question: is the distinction between exotic and native species ecologically meaningful? If you can't agree on that, there's no point in going on to ask whether there's such a thing as an invasive exotic species, whethere invasive exotics are a problem, and what, if anything, we should do about it.
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Seems like this question - whether exotics differ (as a group) from natives - would be fertile ground for research. I assume that there have been many studies where someone has addressed this in some sort of a meta-analysis, but am not personally familiar with those studies (nor with what they found). I suspect, however, that it is more productive to look at this issue on a case-by-case basis as Meiss and Silvert imply. That is, not all exotics are invasives that damage native communities, and some might have valuable functions for sustaining biodiversity. Mark D. Dixon Assistant Professor Department of Biology University of South Dakota Vermillion, SD 57069 Phone: (605) 677-6567 Fax: (605) 677-6557 Email: mark.di...@usd.edu -Original Message- From: Ecological Society of America: grants, jobs, news [mailto:ecolo...@listserv.umd.edu] On Behalf Of James Crants Sent: Tuesday, May 11, 2010 11:06 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc Jim Roper, There's a difference between saying that two species are not ecologically equivalent and saying that two categories of species are not ecologically equivalent. If exotic species (as a category) were ecologically equivalent to native ones, you would still find that every species would differ from every other species by at least a few measures. I'm saying that, as a category, exotic species are ecologically different from native ones. I am deliberately leaving this difference vague because the term ecologically different can serve as an umbrella for all kinds of differences that are relevant to interactions among organisms and between organisms and their environment. Specific differences I would expect to find include: (1) exotic plants have fewer insect herbivore species and lose a smaller percentage of their biomass to insect herbivores than native plants, and (2) exotic species have fewer pathogens than native species. Similarly, I am using vague terms like behave and matters because I want to include a wide array of phenomena, though I suppose you could reasonably argue against the idea of species behaving on the grounds that behavior is something individual organisms or closely connected groups of individuals do. I think most of the confusion in this conversation comes from the fact that Matthew Chew and I just don't agree on whether there's any ecological difference between exotic species and native ones. If they aren't, then what's the point in investing time, money, and energy in controlling exotic species or propagating natives? William Silvert, I didn't really mean to disagree with your fuzzy definitions. In fact, I like them, and I think you could get some ecological insights by using those definitions that you could miss with artificially clear distinctions. Also, I've said more than once that, if we have to throw out any term with indistinct boundaries, we won't find we have much at all left to discuss in the field of ecology. We would not be able to talk about forests, pollinators, the Mediterranean Sea, etc. I just wanted to emphasize, in anticipation of certain everything's the same as everything else arguments that have come up before, that there's a difference between categories with fuzzy boundaries and categories that are totally indistinct and therefore meaningless. One of the keys to arguing against controlling invasive exotic species is destroying the moral arguments that motivate people to bother in the first place. To do this, it helps to use clever language to blur the lines between categories to the point where it's hard to see that native, exotic, invasive, and non-invasive have any meaning at all, except as inflammatory terms used by people who want to manipulate your emotions. The same basic approach is used to stop people doing anything about global warming (e.g., the globe warms and cools all the time; without global warming, earth would be frozen and hostile to life; why do we get excited about human CO2 emissions and not volcanic ones?), species extinctions (repeat the above, modifying appropriately), deforestation (repeat), and so on. For that matter, blurring the lines between humans and everything else (humans are part of nature) is very effective. For one thing, humans ARE a part of nature, and we do cause some harm by saying we're not. For another, it's easy to reduce this down to humans are just another animal, thus ignoring our truly exceptional intellectual abilities and capacity for empathy and moral thought. Anyway, I wanted to head off these sorts of defitions-so-fuzzy-they-mean-nothing, not to disagree with the definitions you gave. As for oceans merging, I can't see a big ecological distinction between the Mediterranean joining the Alantic without human intervention and humans building the Suez and Panama Canals. If anything, I bet the Mediterranean-Atlantic merger was more ecologically dramatic
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
To go straight to the meat of the issue: William Silvert wrote on 11-May-10 11:31: One of the greatest invasions in ecological history occurred when the Mediterranean connected to the Atlantic Ocean. How fundamentally different is that from the opening of the Suez or Panama canals? Well, sure, but trivially so. We are only talking about rates here. And, the fact that we will lose diversity and richness and local history as a consequence of our introductions. But, over geological time, it's just a drop in the bucket. Indeed, your argument, taken to its extreme is, well, since the big bang, all kinds of things have happened and until the big freeze they will continue, so why does it matter what happens in our lifetimes? Clearly we need to define the word matter as in what does it matter. Cheers, Jim
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
What, then, is the ecological difference between humans as a dispersal agent, and, say, seabirds as a dispersal agent? When we study Hawaiian native plants, are we not studying how natural selection influenced organisms after their introduction, or as a consequence of the introduction of other species? The system is still one of an organism having been brought to some isolated location to which it could not otherwise have gotten on its own. The whole study of island biodiversity is inherently the study of introductions of alien species by various means, except in the case of continental islands formerly connected to the mainland. Jason Hernandez East Carolina University --- On Tue, 5/11/10, ECOLOG-L automatic digest system lists...@listserv.umd.edu wrote: But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. Clearly this is a mere consequence of the short history of humans as dispersal agents on the planet, but it is a good enough definition for 99% of the cases - just check the classic by Elton. We already have the term naturalized which basically means it's here to stay and there is nothing we can do about it. I personally think that for almost all intents and purposes, those definitions work. When they don't work, we are either splitting hairs or don't have clear objectives. I think a clear consequence of this, is that humans should avoid introducing and we should often actively eliminate introductions. But, that idea is based on the premise that we want nature to run its course without human help - but that is not a universally accepted premise. And, a second premise is that evolution by natural selection and how nature may have influenced that through genetic drift, lateral gene transfer or what have you, is what is interesting about nature. I can see a future in which ecologists merely study how natural selection influenced organisms after their introduction, or as a consequence of the introduction of other species. Boring. After all, those will always be on a short term scale and will only illustrate what we probably already know about evolution. The big picture, long term consequence of continental drift, punctuated equilibrium and so on, which have resulted in the fascinating diversity of life, do not occur in one or two human generations - but we can certainly wipe out the evidence of them in the same short time frame. Extinctions and introduced species will do just that. Cheers, Jim
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Is a species (possibly) exotic only if introduced by humans? Certainly invasive species can come by natural means -- presumably when the land bridge between Siberia and N. America emerged from the sea there was an invasion of new species (including humans). Less dramatic natural events can bring in new species, or they may arrive because they evolve longer flight ranges or greater temperature tolerances. I think that we are getting too wrapped up with irrelevant rigor in this discussion. A species is exotic if it is outside its normal range, and it is invasive if its local population is growing. Those of you familiar with my work on fuzzy logic may detect that this is a fuzzy definition -- we cannot draw a sharp distinction between native and exotic, some species are more exotic than others, and there are degrees of invasiveness. Is the distinction ecologically meaningless? Not if it has value in understanding an ecosystem. For example, sometimes tropical species show up off the Atlantic coast of Canada due to entrainment in warm-core rings in the Gulf Stream. They are exotics, rarely found, but they can have an impact on the ecosystem. Bill Silvert - Original Message - From: James Crants jcra...@gmail.com To: ECOLOG-L@LISTSERV.UMD.EDU Sent: segunda-feira, 10 de Maio de 2010 16:51 Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc In our conversation, Matthew Chew argued that the distinction between native and exotic species is ecologically meaningless. A species does not have higher fitness because it is dispersed by humans instead of other agents. Most species dispersed by humans fail utterly in the new environment to which they were dispersed. Very few species are evolutionarily specialized for human-mediated dispersal ...
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
There is no way to avoid a value judgement in the whole IAS issue, a certain amount of objectivity is useful but really it is a management orientated discipline, you are not interested in whether a species is alien per se but whether it is having a negative impact on values you hold dear. Usually I focus on valued native biodiversity. That is the point! In the same way extinctions are natural at some level you could say that a human mediated extinctions are no less natural, but for me I can say it doesn't seem the same, even if there were a functionally equivalent alien species to take its place? I could explain why it seems important to save species and ecosystems but you would have heard it all before. I would say we don't know enough to define functional equivalence with confidence. Dr Chew is known for his critcisms of the invasive species concept, issue and science and he puts up some solid arguments. Somehow after having worked in NZ, Galapagos and Hawaii it really does seem to be an issue of importance and a scientific approach adds value, and is therefore valid whether or not the semantics and terms are agreed. Define your question, terms and your assumptions and go for it, probably most fields of science are heavily value driven. Avoiding bias will only take you so far, its a worthy goal that we strive for probably without ever quite reaching it. PS: There is no evidence that the proportion of aliens that naturalize or become widespread will not increase for the forseeable future as long as we continue to move spp to new site, after all if it grows in a location (outside) the real question is why wouldn't it reproduce, establish and spread? On 5/10/10, James Crants jcra...@gmail.com wrote: Jim and others, In the discussion off-forum, we were unable to come to any conclusions because we could not agree on answer to even the most fundamental question: is the distinction between exotic and native species ecologically meaningful? If you can't agree on that, there's no point in going on to ask whether there's such a thing as an invasive exotic species, whethere invasive exotics are a problem, and what, if anything, we should do about it. In our conversation, Matthew Chew argued that the distinction between native and exotic species is ecologically meaningless. A species does not have higher fitness because it is dispersed by humans instead of other agents. Most species dispersed by humans fail utterly in the new environment to which they were dispersed. Very few species are evolutionarily specialized for human-mediated dispersal (I think exceptions would be some of those species we use as crops, pets, and livestock, and some agricultural weeds that have evolved such that their seeds are difficult to separate from crop seeds). An invasive exotic species shows the population dynamics you would expect for any species that is rapidly expanding its range, regardless of its origin. If exotic and native species are not biologically distinguishable, then the distinction is merely historically incidental. The categories are not ecologically meaningful, and they are only useful for marshalling support for one group of plants (natives) and opposition to another (exotics). Actually, Dr. Chew adhered strictly to the term alien. Many people write and talk about alien species, and this term, as well as the term invasive, provoke hostility. They do not serve us well if we want to discuss these things rationally. On the other hand, since Dr. Chew considers these terms to be ecologically meaningless, he is not obliged to suggest alternatives, and he does not. I use exotic instead of alien because it seems less inflammatory, but Dr. Chew and I agree (I think) that there is no way to discuss exotic and native species without ending up favoring one category over the other, regardless of what labels we put on them. That's my summary of Dr. Chew's arguments, as I understand them. As he amply demonstrated in the off-forum discussion, he can make his case much better than I can. I have CC'ed him because I don't think he's on this forum, and he might want to make his point in his own words. Initially, my argument was on moral grounds: whatever negative effects invasive species have on native species are the fault of our species (unless a non-human disperser was responsible for the intial long-distance-dispersal event, which very rarely happens), and, as moral agents, we are obligated to try to undo or mitigate the harm we cause to others. That's my Catholic upbringing speaking, I guess, and it's apparently not a compelling argument to someone who hasn't already reached the same moral conclusion on exotic invasives. I was working on a factual argument against the assertion that exotic species are not ecologically different from native species, but I have not had time to check what I believe to be true against the evidence. Maybe others can help on
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Ah Jim, But that question is easy to answer. If humans put the species in a place or it arrived in a place that it would not have gotten to on its own, then it is introduced, otherwise it is native or natural. Clearly this is a mere consequence of the short history of humans as dispersal agents on the planet, but it is a good enough definition for 99% of the cases - just check the classic by Elton. We already have the term naturalized which basically means it's here to stay and there is nothing we can do about it. I personally think that for almost all intents and purposes, those definitions work. When they don't work, we are either splitting hairs or don't have clear objectives. I think a clear consequence of this, is that humans should avoid introducing and we should often actively eliminate introductions. But, that idea is based on the premise that we want nature to run its course without human help - but that is not a universally accepted premise. And, a second premise is that evolution by natural selection and how nature may have influenced that through genetic drift, lateral gene transfer or what have you, is what is interesting about nature. I can see a future in which ecologists merely study how natural selection influenced organisms after their introduction, or as a consequence of the introduction of other species. Boring. After all, those will always be on a short term scale and will only illustrate what we probably already know about evolution. The big picture, long term consequence of continental drift, punctuated equilibrium and so on, which have resulted in the fascinating diversity of life, do not occur in one or two human generations - but we can certainly wipe out the evidence of them in the same short time frame. Extinctions and introduced species will do just that. Cheers, Jim James Crants wrote on 10-May-10 12:51: Jim and others, In the discussion off-forum, we were unable to come to any conclusions because we could not agree on answer to even the most fundamental question: is the distinction between exotic and native species ecologically meaningful? If you can't agree on that, there's no point in going on to ask whether there's such a thing as an invasive exotic species, whethere invasive exotics are a problem, and what, if anything, we should do about it. In our conversation, Matthew Chew argued that the distinction between native and exotic species is ecologically meaningless. A species does not have higher fitness because it is dispersed by humans instead of other agents. Most species dispersed by humans fail utterly in the new environment to which they were dispersed. Very few species are evolutionarily specialized for human-mediated dispersal (I think exceptions would be some of those species we use as crops, pets, and livestock, and some agricultural weeds that have evolved such that their seeds are difficult to separate from crop seeds). An invasive exotic species shows the population dynamics you would expect for any species that is rapidly expanding its range, regardless of its origin. If exotic and native species are not biologically distinguishable, then the distinction is merely historically incidental. The categories are not ecologically meaningful, and they are only useful for marshalling support for one group of plants (natives) and opposition to another (exotics). Actually, Dr. Chew adhered strictly to the term alien. Many people write and talk about alien species, and this term, as well as the term invasive, provoke hostility. They do not serve us well if we want to discuss these things rationally. On the other hand, since Dr. Chew considers these terms to be ecologically meaningless, he is not obliged to suggest alternatives, and he does not. I use exotic instead of alien because it seems less inflammatory, but Dr. Chew and I agree (I think) that there is no way to discuss exotic and native species without ending up favoring one category over the other, regardless of what labels we put on them. That's my summary of Dr. Chew's arguments, as I understand them. As he amply demonstrated in the off-forum discussion, he can make his case much better than I can. I have CC'ed him because I don't think he's on this forum, and he might want to make his point in his own words. Initially, my argument was on moral grounds: whatever negative effects invasive species have on native species are the fault of our species (unless a non-human disperser was responsible for the intial long-distance-dispersal event, which very rarely happens), and, as moral agents, we are obligated to try to undo or mitigate the harm we cause to others. That's my Catholic upbringing speaking, I guess, and it's apparently not a compelling argument to someone who hasn't already reached the same moral conclusion on exotic invasives. I was working on a factual argument against the assertion that exotic species are not ecologically different from
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Okay, I've taken the bait - or at least, I'm nibbling at it. Earlier today Jim Crants pretty accurately summarized the points I made off-list, for which I thank him. Here I'm responding to his paragraph regarding 'moral grounds' and to his numbered paragraphs (1-4). In order to minimize repeated replies, I've deleted previous material, leaving only specifically relevant passages. I apologize for the inconvenience of having to look up the rest, but it's probably still in your inbox. JC: Initially, my argument was on moral grounds: whatever negative effects invasive species have on native species are the fault of our species (unless a non-human disperser was responsible for the intial long-distance-dispersal event, which very rarely happens), and, as moral agents, we are obligated to try to undo or mitigate the harm we cause to others. That's my Catholic upbringing speaking, I guess, and it's apparently not a compelling argument to someone who hasn't already reached the same moral conclusion on exotic invasives. MC: I think it's safe to assume many or most ecologists feel similarly duty-bound, regardless of their particular religious or ethical training. I suspect (but cannot bring data to bear) that (again) many or most of us now active became ecologists partly because we were already convinced that ethics extend beyond human-human interactions. As a child of the 60s and 70s, I can say that fits my experience, and seems to apply to almost every ecologist I've talked to. Relatively fewer of us have tried to articulate our moral convictions in ways philosophers or theologians would consider to be 'principled', and in my view none of us have really succeeded. Whatever else we are, we're animals with limited capacities. To be very 60s indeed, 'there's nothing [we] can do that can't be done', and evidently quite a lot we can't do. Still, human activity has reconfigured the biosphere. Topologically, it's like wadding up a map of the Earth so that places once all but completely separated are now in all but direct contact. Every major port city touches every other. Every major airport likewise. It's not just the world we live in, it's the world everything else lives in, too. Fundamentally redrawing the map by creating wholly new 'currents of commerce' while expecting former 'rules' of dispersal to persist seems naive. Either our morals are outdated, or our actions are immoral. But neither has much effect on global commerce, and the distinction doesn't matter to anything else entrained in our wake. JC(1) Exotic species, on average, interact with fewer species than native species, and their interactions are weaker, on average. In particular, they have fewer parasites, pathogens, and predators, counted in either individuals or species. This is especially true of plants, and especially non-crop plants. I suspect, but have not heard, that exotic plants also have fewer mycorrhizal associates than native ones, but I doubt that they have significantly fewer pollinators or dispersers. Meanwhile, back in their native ranges, the same species have the same number of associations as any other native species. MC(1) Natural selection only produces interactions good enough to persist under prevailing conditions; there is no gold standard. By definition, 50% of all species interact with fewer species than average, and 50% of all interactions are weaker than average. Preferring stronger, more complex interactions means preferring more tightly-coupled (and therefore) 'riskier' systems with a higher likelihood of failure. JC(2) Very-long-distance dispersal by humans confers a fitness advantage over very-long-distance dispersal by other agents, on average, for two reasons. First, humans often disperse organisms in groups, such as containers of seeds, shipments of mature plants and animals, or large populations contained in ballast water, allowing them to overcome the Allee effects (lack of mates, inbreeding depression) their populations would face if introduced as one or a few individuals. We also often take pains to maximize the establishment success of organisms we disperse, by shipping healthy, mature plants and animals and propogating them when they arrive, while non-human dispersal agents usually introduce small numbers of organisms, often nowhere near their peak fitness potential (e.g., seeds, spores, starving and dehydrated animals). MC(2). JC appears to be arguing that once rare occurrences are no longer rare. I agree. But I draw the opposite conclusion, because he is arguing that to generate such changes is morally wrong, while I am just saying: when these conditions prevail, long distance dispersal becomes normal. JC(3) Although the population dynamics of invasive species do not differ by what agent introduced them (whether humans brought them, some other agent did, or they evolved in situ), it is ecologically consequential that human activities are generating so many more invasive species than
Re: [ECOLOG-L] Ecology Terminology and associated phenomena Colonizing species etc
Wayne, and others, This email was nebulous enough to where it appears to me that several concepts are being bantered around to the detriment of resolving any. Of course all terms are relative - we humans made up language to put names on things to help us. The problem of invasive species is important or not, depending on your particular philosophy, so you would have to come to some common grounds first to resolve what invasive is second. The problem of invasives is just like the problem of endangered species. 99% of all species that ever lived are extinct, so we know that it is a consistent evolutionary process. Probably 99% of all species that exist started out somewhere else. However, the glitch is that in our generation, we are causing the extinction of many species at a much more rapid rate than nature ever did, and we are causing the introduction of species in new places at a rate much more rapid than nature ever did. As Elton in his classic book on introduced species stated (here paraphrased), Because of introductions and their consequences, we will be left with a world much simpler, much less diverse, and much less interesting. Sincerely, Jim Wayne Tyson wrote on 07-May-10 16:47: Ecolog: Back on April 12, 2010, I posted an enquiry along these lines that resulted in an off-list discussion between three Ecolog-l subscribers and three others. A lot of interesting points were made, but this side discussion did not, in my view, settle the matter of what terminology, if any, should be used to describe the ecological phenomena associated with plants (and other organisms) that colonize or invade parts of the earth upon which they did not appear/evolve before dispersal by human culture (including various artifacts and impacts and domesticated plants and animals and their cohorts). Since the off-line discussion did not seem to resolve the issue beyond opinions, I am submitting my version of the results for consideration by the Ecolog community. Among the points (you can ignore these, but they give SOME idea of where the discussion wandered) made by various correspondents were: 1. Persistence is an interesting problem, since it requires an arbitrary stipulation. Fitness is demonstrated (or not) generation by generation. 2. . . .why ARE so-called natives of a higher value than so-called exotics? How far back are we supposed to go before something is considered native? 3. . . . humans should learn how the land works, make minimal changes and only necessary ones, and try to adapt to the landscape as best as possible, using history's lessons to create our future. Trying to make zero footprint or impact or change as we live our lives is like trying to swim without getting wet or making ripples. 4. Eventually Albert Thellung split 'aliens' into 7 distinct categories in 1912: ergasiophytes, ergasiolipophytes, ergasiophygophytes, archaeophytes, neophytes, epecophytes, and ephemerophytes; plus two more denoting 'wild' plants growing in modified habitats. Search any of them and they'll pop up in recent central European literature, but they're dead letters in the Anglophone world. 5. Alien and invasive are both relative. The labels are relevant only in areas where new populations have (respectively) appeared, and spread in some discomfiting manner. They provide no information about any biological essence of any species . . . 6. What matters is fitness under prevailing conditions. 7. . . . the whole question of what response to invasive species is morally best is beside the point. 8. For now, I still believe that each of these terms reflects an objective reality, but that each has nebulous boundaries. 9. The danger of separating natural from artificial mentally might be that we think we have to exclude nature wherever we go. The danger of not separating them is that it can help us rationalize an anything-goes approach to natural systems. 10. Have we decided on any definitions, or are there still differences about terminology? Are we ready to list them yet, even if with a multiplicity of definitions? Either way, it looks like we're making entertaining progress in the realm of associated phenomena. Maybe that's the first, if indirect, hurdle in gaining a workable set of terms? 11. My question is, what belongs there, and why? 12. . . . the important thing is to keep the lines of communication open--ESPECIALLY with those who have alien ideas. 13. Once an idea catches on, it's next to impossible to replace it with another one--something like the tenacity of an alien species--or, one might also say with equal validity or spin, that, like the popular pastime of reasoning by analogy, that it is an example of resistance to invasion. 14. I am interested in the question of whether we ought to subsidize the unfit, and suppress the fit. My own summary interpretation of some of the various conclusions are: 1. All organisms move from place to
