Here are what I see as some problems with the idea that homosexuality
in humans is rooted in the genetics of kin selection, as proposed
earlier in this thread.
1. Suppose an individual is born with a mutation that makes him/her
inclined to homosexuality and to avoid reproduction. If this
individual then "helps around the nest" he/she may enhance the
survival of near relatives WHO DO NOT BEAR THE GENE, since the
mutation is new. How would this mutation enter the population?
2. Insofar as the kin-selection mechanism requires restricted gene
flow, how can we assume that this condition prevailed for our
wondering, hunter-gatherer ancestors? Wondering groups don't have to
be in contact very long to exchange mates or rape each other.
3. It's not clear that an individual's personal inclination to engage
in mating behavior would have much to do with whether they actually
mated. I refer, of course, to rape, but also other forms of social
persuasion. Also, just because a few males in the group may prefer
each other to females, that doesn't mean the remaining males couldn't
keep all the females pregnant, thus favoring their genes over the
non-players.
4. The hypothesis, as presented in this thread, seems to rely on early
populations having been resource-limited, so they would benefit from
decreasing the number of mouths to feed. But isn't it also possible
that they were NOT resource limited. If migratory groups were
expanding into new territory, they might have faced abundance of
resources, especially as their tools and weapons made more things
available to them. Also, given the defenselessness of naked humans or
pre-humans when unarmed, and the dangers of hunting nasty animals when
armed, it is quite possible that those early populations were limited
by predation and traumatic injury. In that case, limiting
reproductive output would seem to be very unfavorable.
I realize that some of these hypothetical conditions, if they
obtained, might tend to contradict each other, or cancel each other
out, but I nevertheless believe they indicate against ready acceptance
of the kin-selection mechanism.
Martin M. Meiss
2013/3/28 Mitch Cruzan <[email protected] <mailto:[email protected]>>
This neglects that fact that homosexuality is not an accident of
history or just a artifact of modern human societies. This trait
is too widespread and occurs at too high a frequency in human
populations to be explained by chance - there must have been a
selective advantage in the past. The widespread nature of this
trait across human populations suggests that it must have been
present in the human lineage by at least the time of the second
major migration of hominids out of Africa around 60,000 ybp. The
inclusive fitness argument mentioned several times by contributors
to this listserve is probably the best explanation for the
maintenance of homosexuality in human populations.
Mitch Cruzan
On 3/28/2013 7:46 AM, Culliney, Thomas W - APHIS wrote:
I was referring to strict homosexuality in humans. Granted,
there probably are cases in which children of a (perhaps
deceased) sibling or other close relative would be raised by a
homosexual, thus raising his or her inclusive fitness, but
such cases would be rare. The Darwinian fitness of a strict
homosexual is, as a rule, zero. Helpers at the nest do forgo
their own reproduction to help relatives raise offspring, but,
as far as I know, there is no requirement for them to be
homosexual.
Tom Culliney
From: Jonathan Colburn [mailto:[email protected]
<mailto:[email protected]>]
Sent: Thursday, March 28, 2013 10:05 AM
To: Culliney, Thomas W - APHIS
Subject: Re: [ECOLOG-L] Exclusive homosexuality
Hi Tom,
Respectfully, the Darwinian fitness sounds like inclusive
fitness, which is often measured by reproductive success.
However, reproductive success of a homosexual is not always a
good measure of their inclusive fitness (e.g. helpers at the
nest). Ultimately, any action that staves off fixation of
alleles to zero is about as close as we can come to
determining that something is inclusively fit...
On Mar 28, 2013 9:20 AM, "Culliney, Thomas W - APHIS"
<[email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>> wrote:
I note that the albatross article mentioned the words
"natural" and "normal." Homosexuality certainly is natural, as
it occurs in nature, in animals from groups ranging from
arthropods to mammals (who knows what goes on in the plant
kingdom?). In all cases, there appears to be an adaptive
reason for the behavior. However, in its reproductive
consequences, exclusive or strict homosexuality, as exhibited
in humans, cannot be considered normal sexual behavior. The
Darwinian fitness of homosexuals is zero. To the extent that
there is a genetic component to the behavior in humans, with
their diverse sexuality, the trait undoubtedly persists in the
population largely through the actions of bisexual individuals
leading to the production of offspring.
The above is an argument strictly from a biological
perspective, and is not a moral judgment. What two consenting
adults do in private is their own business and no one else's.
Tom Culliney
-----Original Message-----
From: Ecological Society of America: grants, jobs, news
[mailto:[email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>] On Behalf Of Kristen Dybala
Sent: Wednesday, March 27, 2013 10:55 PM
To: [email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>
Subject: Re: [ECOLOG-L] Expedition notice and question
Laysan albatrosses are a fairly well-known example. Here's a
(lengthy) article describing it:
http://www.nytimes.com/2010/04/04/magazine/04animals-t.html?pagewanted=all
-Kristen
On Wed, Mar 27, 2013 at 6:53 PM, Merav Vonshak
<[email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>> wrote:
This story reminds me of a similar story - a male pair of
Griffon
vultures (Gyps fulvus). They incubated eggs and reared
other pairs'
youngs as part of a breeding in captivity effort in Israel
some years ago.
Merav
Merav Vonshak
Postdoctoral Fellow
Gordon Laboratory
Department of Biology
Stanford University
Stanford, CA 94305-5020
Phone: 650-725-6791 <tel:650-725-6791><tel:650-725-6791
<tel:650-725-6791>>
email: [email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>
http://www.stanford.edu/~mvonshak
<http://www.stanford.edu/%7Emvonshak>
On 27, Mar2013, at 12:08 PM, Montblanc, Genie wrote:
WT,
Since I don't study this, I'm giving a, "What I've
heard in the news,"
response. There were two stories awhile back, both
relating to
animals in captivity, about homosexual pair bonding. One
was with
penguins, I think they also raised a chick together, and
the other was
with dolphins. Given that long-term pair bonding only
occurs in 8-11
species in the entire animal kingdom, the question might
be moot anyway.
That is my inexpert response. Have a great expedition!
Génie
Eugénie MontBlanc
Great Basin Fire Science Delivery Coordinator
University of
Nevada/Mail Stop 0186, Reno, NV 89557
Phone: 775-784-1107
<tel:775-784-1107><tel:775-784-1107
<tel:775-784-1107>> (Fax: -1109)
Email: [email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>
Web: www.gbfiresci.org
<http://www.gbfiresci.org><http://www.gbfiresci.org>
Twitter: @GBfirescience
-----Original Message-----
From: Ecological Society of America: grants, jobs,
news [mailto:
[email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>] On Behalf Of Wayne Tyson
Sent: Wednesday, March 27, 2013 10:32 AM
To: [email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>
Subject: [ECOLOG-L] Expedition notice and question
[NOTE:] I will be on expedition (with a stop at the
National Native
Seed
Conference in Santa Fe NM on April 10) until the two weeks
at the end
of April and the first week of May, then gone again
beginning the 2nd
week of May until around May 24. I will not be checking
email during
those periods, but will respond to as many email messages
as possible
during those hiatuses. A third expedition following those
is likely,
but the period of hiatus is iffy.]
Here is my parting question. Please feel free to post
it on other lists.
Re: Homosexuality in animals other than Homo sapiens.
We know that
homosexual behavior occurs in other species in some forms
(Bonobo
chimpanzees [Pan paniscus], for example), and we know that
hermaphrodites of some species fertilize each other
simultaneously.
But my question is in which species other than humans,
does EXCLUSIVE
homosexuality, especially in the form of pair bonds, occur?
WT
I'll pick up my answers in late April. If I have time,
I may be able
to
respond to some today. Please respond on-list, and not to
me personally.
--
----------------------------------------------------------
Kristen Dybala, Post-doctoral Researcher Museum of Wildlife
and Fish Biology University of California, Davis
[email protected]
<mailto:[email protected]><mailto:[email protected]
<mailto:[email protected]>>
(415) 218-9295
<tel:%28415%29%20218-9295><tel:%28415%29%20218-9295> - cell
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