Re: [ECOLOG-L] Exclusive homosexuality

[Mitch Cruzan]

Homosexuality may be maintained in different species for different 
reasons.  It's probable that the case for humans was different because 
of our unique history. Fitness is not just based on individual 
performance, but an individual may increase their fitness through their 
relatives (termed 'kin selection' or 'inclusive fitness').  Survival of 
our hominid ancestors depended on living and working in groups, which 
tended to be highly inbred as migration of individuals among clans was 
probably uncommon. This situation was exacerbated by the fact that our 
offspring are extremely altricial - requiring many years of parental 
care before they can feed themselves.  Clans that included individuals 
who did not participate in reproduction, but helped procure food and 
care for the young would have had a selective advantage.  There are lots 
of examples of inclusive fitness in other species - colonial birds where 
juveniles are 'helpers at the nest.' The difference is that in these 
colonies the juveniles will probably reproduce when they are older.  The 
best analogy to ancestral humans may be naked mole rats - inbred 
colonies survive in the harsh deserts of Eastern Africa.  Workers in the 
colony never reproduce, so the system is maintained by inclusive 
fitness.  Certainly there are other reasons for the maintenance of 
homosexuality and bisexuality - the above is just one plausible scenario.

Mitch Cruzan

On 3/28/2013 5:27 AM, Culliney, Thomas W - APHIS 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:ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Kristen Dybala
Sent: Wednesday, March 27, 2013 10:55 PM
To: ECOLOG-L@LISTSERV.UMD.EDU
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 <merav...@gmail.com> 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
email: mvons...@stanford.edu
http://www.stanford.edu/~mvonshak

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 (Fax: -1109)
Email: e...@cabnr.unr.edu
Web: www.gbfiresci.org
Twitter: @GBfirescience

-----Original Message-----
From: Ecological Society of America: grants, jobs, news [mailto:
ECOLOG-L@LISTSERV.UMD.EDU] On Behalf Of Wayne Tyson
Sent: Wednesday, March 27, 2013 10:32 AM
To: ECOLOG-L@LISTSERV.UMD.EDU
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 kedyb...@ucdavis.edu
(415) 218-9295 - cell





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