Every Vertebrate Is Just a Little Bit Gay

[Aldebaran]

Could it be that homosexuality becomes more commonplace (more gay animals/people are born) when a species begins to fill up it's available localized living space? That would be a clever way for evolution to naturally prevent overpopulation. I'm pretty sure evolution doesn't work that fast, though... so probably not.

Great article. Thanks Jack.

Posting this in the hope that the work of John B. Calhoun and his rats of NIMH isn't old-hat to everyone here. Calhoun pretty much performs the experiment you'd expect: put way too many rats in a cage and see what happens.

Here is what happens:

Initially the population grew rapidly, doubling every 55 days. The population reached 620 by day 315, after which the population growth dropped markedly. The last surviving birth was on day 600. This period between day 315 and day 600 saw a breakdown in social structure and in normal social behavior. Among the aberrations in behavior were the following: expulsion of young before weaning was complete, wounding of young, inability of dominant males to maintain the defense of their territory and females, aggressive behavior of females, passivity of non-dominant males with increased attacks on each other which were not defended against. After day 600 the social breakdown continued and the population declined toward extinction. During this period females ceased to reproduce. Their male counterparts withdrew completely, never engaging in courtship or fighting. They ate, drank, slept, and groomed themselves – all solitary pursuits. Sleek, healthy coats and an absence of scars characterized these males. They were dubbed “the beautiful ones”.

Males became aggressive, some moving in groups, attacking females and the young. Mating behaviors were disrupted. Some males became exclusively homosexual. Others became pansexual and hypersexual, attempting to mount any rat they encountered. Mothers neglected their infants, first failing to construct proper nests, and then carelessly abandoning and even attacking their pups. In certain sections of the pens, infant mortality rose as high as 96%, the dead can nibalized by adults. Subordinate animals withdrew psychologically, surviving in a physical sense but at an immense psychological cost. They were the majority in the late phases of growth, existing as a vacant, huddled mass in the centre of the pens. Unable to breed, the population plummeted and did not recover. The crowded rodents had lost the ability to co-exist harmoniously, even after the population numbers once again fell to low levels. At a certain density, they had ceased to act like rats and mice, and the change was permanent.

http://www.thefreelibrary.com/Escaping+ ... 0197666893

[Gnomad]

When one sometimes wonders whether the world is just a petri dish or lab cage or a simulation hypercube for some kind of being, experiments like the rat one above tend to make it feel perfectly acceptable.

[AhabsOtherLeg]

Could it be that homosexuality becomes more commonplace (more gay animals/people are born) when a species begins to fill up it's available localized living space? That would be a clever way for evolution to naturally prevent overpopulation. I'm pretty sure evolution doesn't work that fast, though... so probably not...

Posting this in the hope that the work of John B. Calhoun and his rats of NIMH isn't old-hat to everyone here. Calhoun pretty much performs the experiment you'd expect: put way too many rats in a cage and see what happens.

Yep, Aldebaran, it was Calhoun's "behavioural sink" that I was partly thinking of, but I was hesitant to post it since it quite clearly counts homosexuality as a "deviance" from nature, and a "harmful" result of environmental stressors - in fact it places homosexuality on a spectrum of deviance alongside the break-up of family units, increased violence in the community, and cannibalism of the young, which even Pat Robertson might baulk at.

Of course when Calhoun did his study homosexuality was counted as a mental illness by the psychiatric community at large, and was also a crime in most states.

Here is what happens:...

Mating behaviors were disrupted. Some males became exclusively homosexual. Others became pansexual and hypersexual, attempting to mount any rat they encountered

We see this in zoos, among monkeys, with males mounting males, females mounting males, adults mounting their young (and vice versa), apparently just as a form of dominance behaviour, to establish a pecking order - not really for sexual pleasure so far as we know, and definitely not for reproductive purposes. Arguably the same thing is seen in jails among humans, where there is a stratospheric incidence of male rape quite unlike anything seen on the streets (hopefully).

The article you posted mentions the Sika deer on James' Island, but it's a really fascinating case so I wanna talk about it...

A few Sika deer were released onto James Island in Chesapeake Bay in the early 1950s, where there were no predators to keep their numbers in check. Pretty soon they grew into a herd, and the ethologist John Christian went to study them in this uniquely safe environment, where no outside force (except him, funnily enough) could prey on them. Problem was, the island was only 280 acres in size, with no means for any excess population to leave the area, and no room for the growing herd to expand into. The Sika deer didn't become violent, hypersexual, or homosexual (so far as we know) and nor did they eat their young - they're not predators or scavengers like rats are, so their reaction was different, and initially inexplicable. In the first three months of 1958 more than half the herd simply dropped dead.

Autopsies carried out on 161 of the dead deer showed that the animals had vastly enlarged adrenal glands. They had been living in a state of constant stress, a perpetual fight-or-flight reaction, despite the absence of any real predators or threats on the island. A large portion of the population had suffered spontaneous heart failure as a result.

The only explanation for this that Christian could think of was overcrowding (I doubt he even considered pollution of the water around the island, which could've been a factor. His own hunting of the deer with a rifle in such a confined area could've had something to do with stressing them out as well.)

The physiological (and consequent behavioural) changes in the deer population were sudden and unexpected, though, definitely not genetically herited or evolutionary but just there one day. The changes were also quite quickly reversed after the population crash, so that deer carcasses examined just a few months after the die-off were found to have adrenal glands 46% smaller than those of the deer that had died in the "crash". It was as if the survivors were returning to normal after the "pressure" of overpopulation had been removed. Nature had corrected their exponentially growing numbers by (quite abruptly) changing their physiological chemistry to the extent of killing half of them off. Or so the theory goes.

(http://books.google.co.uk/books?id=vMh0 ... ds&f=false)

I'm not sure I'd want to apply any of that to human (or even animal) homosexuality though, except as a (quite creepy, now that I read it back) theory.

[Allegro]

.
Thanks, Jack!

Relevance!

...we were having a discussion in this thread about evolution, here's an interesting article. I shall not copy-paste the whole interview but just the top and the key parts on the paradigm shift itself, in Shapiro's view. Go to the link to catch all the interesting politics they also discuss...

Here’s a James A. Shapiro lecture on vimeo: Revisiting evolution in the 21st Century. The visual isn’t good but not bad; the audio is clean. The Q&A begins at 1.12.46. I’ve added below the pdf’s noted on the vimeo page.

← Uploaded one year ago [VIMEO NOTES.] New research has shown that a novel way of looking at evolution is needed. Cells are sensitive and communicative information processing entities. Novelty in evolution comes in part from genome changes that are the result of regulated cellular activity. The next step in the understanding of evolution is emerging since the Modern Synthesis of Darwinism and Mendelism and the discovery of the double helix structure of DNA in the middle of the last century.

PDF. Here are the slides of this lecture

PDF. This is the latest research paper on the subject with more detail

shapiro.bsd.uchicago.edu

James A. Shapiro is a the founder of the concept of Natural Genetic Engineering
Department of Biochemistry and Molecular Biology
University of Chicago
Gordon Center for Integrative Science

There was also a conference on this subject in 2008

All conference papers are available here

Edit. University of Chicago references