Intellectual smintellectual: Evolution

A online conversation with A. Prof John Elliot (JE):

Me: Dear Sir,

Might I just ask something which may not seem to be of relevance but is rather interesting? I remember you saying in lectures that homosexuality is something that is more and more obviously shown to be linked to biological reasons.

I was revising for another module yesterday when i chanced upon an article that challeges that homosexuality can be traces to genetics/biology. The writer argues and wonders how evolution would allow for such genes to be passed down if, from an evolutionary perspective, human beings are made to reproduce and therefore passing such genes down would not be beneficial at all...

So in that case, gender/sexual orientation is then determined by psycho/socialisation etc?

Personally, Im quite on the fence really. But it would be interesting to hear what you think about this, especially about the evolution bit...

Thanks!

JE: Its a very good question. The existence of biologically counterproductive conditions is difficult to account for within an evolutionary perspective, because they clearly do not have any reproductive survival value. Several suggestions have been made for the case of homosexuality, all of which suggest that it is an incidental consequence of some other advantages. Here are three possibilities (this is not ehxaustive):

1. homosexual people 'invest in' (help) their relatives because they do not have children of their own. families with a proportion of homosexual children may therefore end up caring for them better than those which do not. The main objection to this is that there is little evidence to support it.

2. that homosexuals tend to be more creative, and that these things are genetically linked, so that the chances of being gay increase if you are creative, but that creativity is a useful quality, it helps you invent new tools, discover new things, and generally is of value; it may also be of value in attracting mates. On this view honosexuality is an occasional side effect of creativity. It too lacks evidence, though.

3. that women who have homosexual sons are also more fertile, and espcially, have more daughters. There is evidence for this published recently in the Proceedings of the Royal Society, though I do not have the reference handy at this momnet. On this view, homosexual sons are a side effect of advantageous fertility, and the benefits (in total numbers of offspring) outweigh the costs (of some of them never having children of their own). This is the least speculative account; it accounts only for male homosexuality.

Regards

John Elliott

Me: I see. So if that is the case, homosexuals make up for their inability to contribute to continuity (reproduction) by serving some function or other.
Thanks!

JE:Not under option 3.

Me: Actually I dont quite agree that they dont serve a function with regard to point number 3.

Since they are not inclined to reproduce, and even if they did, they would be less fertile (as mentioned in your reply to Zijun), then perhaps, in some way, they serve as somewhat of a 'population control' to make up for the fact that their mothers are very fertile.

This is highly speculative on my part but could that be a possibility?

JE: Well, this suggestion does not make sense in evolutionary theory, because there is no design for the good of the species or to control populations in that theory. Evolution is not about what's good for the species, it is about the unintended consequences of differential reproductive success of individuals.

Of course, viewed from a social perspective one could say that population control was helped by the existence of homosexual individuals. But that is not their biological function, and its not why they exist, which was the original question to be answered.

JE

Me: Well, perhaps my conception of what evolution is all about requires more thinking.

I mean if we are not evolved for the good of the species then why do we have natural selection? Which correct me if im wrong, is essentially about preserving the 'good stuff' and getting rid of the non-beneficial traits.

Which was what therefore led me to pose that question in the first place. But I think I am grasping what you mean (i hope), in that in the end, it is ultimately about unintended outcomes of reproductions, which would perhaps then, serve as a platform for futher refinement in future?

In any case, thank you very much for entertaining my queries. I've always been intrigued about this topic!

JE: We ae not evolved "for" anything. We are just evolved! What you see is the result of a process of evolution, but it was undertaken with anything in mind.

Well, you can always do PL4214, if you do honours, or UAS3006 if you are a scholar.

JE