Tiny mutation may have shaped modern humans, scientists say

[struggle4progress]

A genetic variant could have helped people survive crippling heat by giving them extra sweat glands, says a report from a team that sought to replicate the effect in mice.

By Eryn Brown, Los Angeles Times
February 14, 2013, 4:59 p.m.

About 30,000 years ago, a tiny mutation arose in a gene known as EDAR and began to spread rapidly in central China, eventually becoming common in the region.

This week, scientists at Harvard University offered some explanations for why the EDAR mutation may have been so successful — by observing how it affects mice, animals long used in disease research but never before pressed into service for the study of human evolution.

The small change, substituting one chemical letter of DNA for another, may have helped humans in Asia survive crippling heat and humidity by endowing them with extra sweat glands, the scientists reported Thursday in the journal Cell. It may also have made people with the mutation more attractive to the opposite sex by allowing them to grow thicker hair or fuller breasts.

The research showed how scientists are getting better at zeroing in on the key DNA changes that shaped who we are today. The analysis also revealed that mutations in genes involved in bone density, skin color and immune system function were likely pivotal in helping humans adapt to new environments as they spread throughout the world ...

http://www.latimes.com/news/science/la-sci-human-evolution-genes-20130215,0,7710369.story

[Drale]

1. Another interesting mutated gene

is the one that creates blue eyes and that has only been about for between 10,000 t0 6,000 years.

[AverageJoe90]

5. Not for just 10,000 years.

I remember that study, btw. Sorry, but the theory that all of the blue eyed people in the world came from just this one man in today's Romania, falls flat on it's face; because, in fact, there have been people with blue eyes over the world, including in places where Europeans had never even conceived of before well after the age of civilization had started, such as Iran, India, or even parts of Africa, etc.

I'm not necessarily saying that it didn't have a single origin point, but that it was certainly earlier than 10k years ago, that much cannot be serious debated.

[libodem]

2. Interesting

Hmmm?

[Jim__]

3. Are we talking about all modern humans? Or just Asians? Or, more specifically, just Chinese?

If this mutation is mostly found in Chinese, wouldn't we expect them to have thick hair (thicker than people without the mutation, or at least thicker than Chinese without the mutation), to sweat more than other people, and the women to be big breasted? I've never considered these to be common traits among Chinese - but maybe Chinese from Central China exhibit these traits. In that 30,000 years did China go through a hot spell so that these extra sweat glands would have played a life-saving role?

The article doesn't convince me that they've actually found the reason that this genetic mutation was successful. It may be that the actual report in Cell is more specific.

[dipsydoodle]

4. That's also

how coarse grass became wheat - a mutation.