Saturday, February 02, 2013

The 10,000 Year Explosion

Excellent book.  This goes on the keeper shelf, of things I will continue to reference.

Cochran and Harpending's The 10,000 Year Explosion: How Civilization Accelerated Human Evolution not only brings you up-to-date on the application of genetics to anthropology, but engagingly explains how complicated selection mechanisms work. I have long believed that in linguistics and archaeology, anthropologists tend to be among the most resistive to new ideas - much more defensive of territory and much meaner about it than other academics.   Apparently it holds true for the studies of migration, population displacement, and group differences as well.

That's not entirely fair of me.  My sample is drawn from the topics I read about.  Rheologists or art historians might be worse and I just don't know it.

Still, Cochran and Harpending are clearly swimming upstream against the received wisdom, not only in academe, but in popular understanding as well.  There is a strong desire to believe that evolution worked just long enough so that we can kick Christians about being stupid, and then the process basically stopped, just kind of touching up the human DNA around the edges for the last 50,000, and certainly the last 10,000 years.  It all moves vewwy slowly.  We don't need new genes to deal with hot and cold, because now we have electricity, the reasoning goes.

It certainly couldn't do much in time frames under a thousand years, anyway.  Except it does.  We average 10 new mutations apiece, and while most of them are neutral and next-most are bad, there are still lots of good ones in absolute terms, and they can spread quickly. The better they are, the more quickly.

So jump in and enjoy the fun stuff.  Half the world speaks an Indo-European language because that small tribe had a mutation for lactose tolerance and gradually conquered or displaced the rest of us.  Sapiens interbred with neandertalensis and clipped off their best 200 or so genes and shed the rest, speeding us onward to be sapiens sapiens. Ashkenazi Jews are likely smarter because there is a heterozygotic advantage for Tay-Sachs or torsion dystonia, even as being homozygotic for same is destructive.  Only about 25% of human conceptions result in births because the new speed of evolution is making us less genetically stable, and a lot are miscarried early.  You may have run across these ideas before, but here you will have them explained.


Texan99 said...

I read that book last year and enjoyed it thoroughly. Science fiction writers love to play with this idea, but they mostly focus on evolutionary pressure to increase cognitive ability. I can't remember any story in which an author explored things like lactose tolerance or resistance to diabetes, or really any mutation that affects our ability to adjust to new food sources.

Dubbahdee said...

Not your larger point, I know. But this article may speak to evolution/mutation in more recent times.

Read about how forks gave us overbites.

Texan99 said...

Dubbahdee: that was an interesting article, and good comments, too.

pacificwaters said...

What is it with you and Christians? If you haven't noticed there are other religions whose tents are even more ludicrous.

pacificwaters said...


Assistant Village Idiot said...

pacificwaters, you misunderstand me. I am a Christian. If you reread the sentence in question you will see that I am making fun of those who kick Christians about evolution and Genesis, but then ignore subsequent evolution themselves.