Wednesday, December 12, 2007

races have been growing more distinct, according to a study.


While this remains true – all humans share more than 99 per cent of their DNA – the new work indicates that variations tend to differ between races, and that these became more, not less, pronounced.

“Human races are evolving away from each other,” said Henry Harpending, Professor of Anthropology at the University of Utah, who led the study.

“Genes are evolving fast in Europe, Asia and Africa, but almost all of these are unique to their continent of origin. We are getting less alike, not merging into a single, mixed humanity..."
And this is the coolest thing ever:
Disease-resistance genes also differ. About 10 per cent of Europeans have CCR5, which confers some resistance to HIV, and which may have evolved to give resistance to smallpox.


emily1 said...

the 'race' angle is way over-played:

... Had the differences turned out to be substantive rather than superficial, that would have been new. But the study wasn't designed to evaluate that. Apart from a few traits like lactose tolerance and skin color, the study didn't account for the character of genetic variations. Neither did it account for modern social and historical trends -- the massive diasporas of the last several hundred years, between-group breeding, the shift from rural to urban living.

But that didn't stop the BBC from putting the notion that humans "are becoming increasingly different" on equal footing with increasing evolutionary rates, and quoting co-author Henry Harpending on continent-specific gene differences. The Times (UK) one-upped the BBC by conflating ethnicity with the notoriously arbitrary concept of race. So did the Salt Lake Tribune, who said the findings "could challenge assumptions regarding racial equality, because they suggest Europe, Asia and Africa produced strains of humanity whose differences are more than skin deep." The Globe and Mail quoted Harpending saying, "Human races are evolving away from each other."

It's understandable that journalists would foreground the race issue. Writing about science is tough: science journalists take high complex findings, try to understand them, determine what's important and how strongly the data supports it, then explain it in a way that makes people care -- all within the space of a few hours, and often in the middle of controversy and contradiction.

But in the aftermath of the James Watson debacle, publications that played up the race angle were irresponsible. Watson's comments on the inferior intelligence of Africans set off a storm of debate about race-based genetic differences. That people would interpret the latest evolution findings as supporting Watson's position was clear. But the study wasn't designed to do that. It couldn't do that. And while the anthropologist Harpending is more entitled than most people to opinions on race and intelligence, they were largely irrelevant to the substance of the study and should have been an afterthought -- or, better yet, ignored altogether.

source here.

emily2 said...

blah, i forgot to add a link, so i had to hunt down my source again. what a pain.


perhaps "race" is the wrong word. actually, it's totally the wrong word. how about "semi-insular groups living in a geographical area with a border, either self-imposed by culture/nationality or a natural border." to which i say, well, of course. people are living beings and they are subject to the same processes in evolutionary biology as all beings, such as adaptation, genetic drift (population bottleneck, founder effect), and others.

also, in certain conditions, some mutations are beneficial and tend to accumulate whereas in other conditions, they are neutral or not very beneficial, and if they are not beneficial, they are reduced by natural selection, either ecological or sexual or both. yadda and yadda.

anyway, groups living in different areas will evolve differently for a variety of reasons.

the race angle is definitely overplayed, and i didn't even realize i used the term in the headline, but what i meant was the really long term i wrote earlier in this comment: "semi-insular groups living in a geographical area with a border, either self-imposed by culture/nationality or a natural border." maybe the term "race" was just a shortcut, albeit an inaccurate one, although using the term "race" seems to get people's blood pressure up and can't be dismissed by the usual, "eh... let's not argue about semantics."

it's so hard to have a neutral discussion about race, ethnicity, and genetically-connected demographic groups.

some people definitely have a racist agenda and want to set up racial hierarchies, and i suspect that others are so afraid of that agenda that they subconsciously fight against any discussion of inherent differences between human beings from a evolutionary biology or genetics standpoint (and ironically, the latter group tends to be the most vocal proponents of teaching evolution in public schools, but i digress).

neither take is very healthy, but hey, that's reality.

anyway, i was really excited about the CCR5 mutation. i'm a dork.

p.s. james watson is 16% black. awesome.

Yvespaul said...

Hi Emily,

just thought you might want to listen to this song by Amy Winehouse called "Back to Black", it was released as a single. Although it is not as catchy as "Rehab", I think it is a better song. Hope you like it:

Cheers, YvesPaul