The future of evolution

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Posted by: stak
Posted on: 2008-02-09 14:08:43

I was reading this article on Wired about how families are shrinking in developed nations, and it reminded me of something that I was thinking about a while ago. It occurred to me that the human race seems to have outgrown natural selection. By now we control enough of our environment that small changes in nature don't really put any evolutionary pressure on us. Yes, there are still catastrophic events that kill thousands of people, but that doesn't really qualify as natural selection, since it kills people based on where they're geographically located rather than selecting against some genetic trait.

But anyway, if natural selection no longer applies to us, then we, as a race, need to find other selection processes in order to keep evolving. I was thinking that on a long enough time scale, the only feasible selection process is self-selection. We're going to reach a point where people who are below average will still be smart enough to realize that they are below average (or more generally, people will be more aware of the quality of their genetic material), and will remove themselves from the gene pool in order to improve it. (Note that by "remove themselves from the gene pool", I don't mean "kill themselves", just that they will choose to not have kids).

However, the point in that article above that struck me was that even though the family size in developed countries is much smaller than in developing countries, there is still a variation. "Even among these highly successful people, the richest of them tended to have bigger families." That is interesting, because it seems to imply a sort of self-selection is already happening in developed nations. People who are rich realize that they are above average and have larger families. Or maybe people who aren't as rich realize that they are below average and have smaller families. Either way, I'm not sure if this is fully conscious decision on their part, of even if it's self-selection at all, but it's an interesting possibility.

The article seems to come to a wishy-washy conclusion saying (as I understand it) that having more children requires more effort and resources, which is why families are smaller, but I don't think that fully explains why richer people would have larger families in the developed countries. Anybody else got any thoughts as to why this might be happening?

Posted by Fai at 2008-02-09 16:46:37

A few comments:

My thoughts are that in poorer families (or traditionally more rural families) kids are more likely to be used for labour so you need several to help out. Also with a higher mortality rate, I think people would have several to ensure at least one offspring survives.

Don't confuse money with genetic worth. The two are not the same

Be careful of making the cirteria too stringent or too tied to certain characteristics. We need diversity as well as competence to survive.

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Posted by stak at 2008-02-09 17:01:12

I agree with the first comment.

I realize that money is not equivalent to genetic worth. However, in today's society, money is generally correlated with success. People who are successful are more likely to view themselves as having a higher genetic worth, whether or not that is true. Self-selection is based entirely on people's view of their own genetic worth, so in this case rich people are more likely to want their genes to stay in the gene pool.

Agreed, diversity is important. Evolution is a slow and very imprecise process, and that's not going to change anytime soon.

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Posted by http://maverichka.myopenid.com at 2008-02-10 22:46:24

good :)

right but just because you think you're successful and have worth does not necessarily mean you do. So money should not be the only metric. Also, money is only a measure of success in capitalistic countries. In other countries, money is a measure of how corrupt an individual/his parents were, which does take a certain skill, but perhaps not the only one that should be promoted to have kids.

indeed.

Posted by anonymous at 2008-02-10 01:46:36

I don't think people decide whether or not to propagate their genes depending on how good they think their genes are. It's the genes that decide to propagate themselves. The ones that are better at doing so will survive. They created us to do this.

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Posted by stak at 2012-01-28 17:40:35

I finally got around to reading The Selfish Gene, and it's a really good book. I agree with his view of things (which is the same as in your comment) and yeah, my post makes no sense at all in that context. I spent a while trying to reconcile the two but the theory in my post depends on some assumptions and a organism-based model that I no longer believe.

However, Dawkins also talks about memes, and those change the game completely. It would be possible for a meme to arise that radically changes the composition of the human gene pool by infecting hosts and preventing a particular subset of them from reproducing. I don't know if you're still reading this blog, but any thoughts on that?

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Posted by Ben at 2008-02-12 23:51:40

I think the only logical conclusion that we can make here, Kats, is that you should have my babies.

Several of them.

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Posted by stak at 2008-02-13 01:02:10

Several of them, huh? I'm sure Kim will have something to say about that one...

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Posted by Fai at 2008-02-13 02:21:16

but one would be ok?

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