Cold Neandertal truths

The Washington Post has an article up on recent controversies regarding the relationship between Neandertals and our own lineage. Nothing too surprising, though I did note one point:

But one genetic trait of modern Europeans makes him [Chris Stringer] doubt there was any major Neanderthal input -- the fact that most humans today are genetically ill-adapted to cold weather. Only some native Indian populations, as well as people in the north of Eurasia and aborigines in Australia (who experience deep cold at night), have good genetic defenses to cold. Since Neanderthals lived in Europe for hundreds of thousands of years, through ice ages and frigid conditions, they would have become genetically suited to such conditions, Stringer said. The fact that Europeans are not, he added, suggests that any Neanderthal contribution to their makeup is limited.

The logic here is that if interbreeding occurred then cold adaptations should have introgressed. I don't know enough about human biology to speak to the veracity of Stringer's assertions about cold adaptations, but let's take him at face value. Let's also assume that some interbreeding did occur. Why didn't northern Europeans end up like Neandertals with a whole suite of cold adapted genetic responses? Well, some did, but in any case, this might be a situation where antagonistic pleiotropy was a significant constraining force. Neandertals might have developed all sorts of genetic responses to cold climates which imposed fitness costs. For Neandertals the costs might have been tolerable because there was no other option. Modern humans on the other hand might have developed alternative strategies (e.g., better clothing) which didn't necessitate these genetic costs.

Addendum: I do want to note that we should be cautious about Stringer's assertion, northern peoples do seem to have cold adapted metabolisms.

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According to this:

http://johnhawks.net/weblog/reviews/genetics/non-primate/arctic_fox_anc…

Neanderthals might not have lived through ice ages, the more northerly populations might have become extinct and been subsequently replenished from the south.

It doesn't say whether the extinctions might have been due to lack of sufficient cold adaptation for very cold climate or due to southerly shift in prey species and changes in flora not suited to Neanderthal ambush hunting.

But we could theorize that Eskimos do fine in landscape that Neanderthals would have had a hard time surviving, for a whole suite of reasons including cold-adapted bodies which seem to be a case of convergent evolution of body morphology rather than interbreeding.

By Sandgroper (not verified) on 02 May 2007 #permalink

Another thing is that Neanderthals were jacked -- muscular as all hell -- and we weren't. Fat is a better insulator, so we already had that advantage.

Sandgroper,

I read that Hawks article too, and while Googling for similar stuff, came across an article that stated that the Irish hare has lived in Ireland for about 23,000 years, while the British hare for only 11,000 years. This is because a Southern Ireland Refugium existed - covering the extreme Southern coastal areas and some of the present Celtic Sea area - which though cold, was ice free for millenia, and formed a largish island off the coast of North West Europe.

Wouldn't this be an ideal place for Neanderthals to live - provided they were sustaining themselves on sea mammals and fish??

Agnostic,

Well Neanderthals were wide hipped and strong, with a body made for endurance, rather than speed. I'd say they were probably fat too, while early moderns were probably leaner then todays average??

pconroy - It's the other way round - Neanderthal was the heavy muscular ambush hunter/fast sprinter with stabbing and chopping weapons, but energy requirements would have been too great over long distances - essentially sedentary and hunting in a relatively small radius. H. sapiens was the much more gracile nomadic long distance runner with greater endurance who ran down smaller prey and had throwing weapons.

This might be of interest:

http://cogweb.ucla.edu:80/ep/NeanderthalParadigm.html

Neanderthals were not exclusively big game hunters though - there is some evidence that they did fish, at least in some places. I don't have a link for that that I can put my hands on immediately, but John Hawks posted something about it a while back.

By Sandgroper (not verified) on 02 May 2007 #permalink

Eskimo culture is relatively new (starting in NE Asia about 500 BC IIRC). They had extensive technical ways of minimizing the effects of cold from the beginning. The most impressive cold adaptation I've heard of was the Indians of Tierra del Fuego, a cool temperate climate which they survived without much in the way of clothing or housing. IIRC they impressed Darwin with their resistance to cold.

What I've always wondered about regarding the Eskimos is their resistance to skin disease. Wearing the same leather clothes for months at a time, they must have got pretty rank. (I think the same of desert people and steppe peoples who never wash). Perhaps they develop a healthful mix of bacteria and fungi, like our intestinal bacteria, with the friendly bugs keeping the nasty ones under control.

By John Emerson (not verified) on 03 May 2007 #permalink

The Tierra del Fuegans smeared themselves with an insulating layer of grease, did they not? They sound a bit like Channel swimmers.

Cool temperate - I think that's what we denizens of the tropics call unbearably cold. I went to Alberta in the middle of summer once and nearly died of the cold, or felt like it. And all the Albertans were jogging around in shorts and no shirt.

Yes, it's not just the clothes either, desert dwellers who never wash and go absolutely stark naked still stink to high heaven.

By Sandgroper (not verified) on 03 May 2007 #permalink

Some interesting stuff. There are many kinds of adaptation to cold, many of them non-genetic.

Adaptation to cold.

By John Emerson (not verified) on 03 May 2007 #permalink

Wearing a seal intestine suit must be nice.

By Sandgroper (not verified) on 03 May 2007 #permalink

Seal intestine suits look snappy, but they're not really comfortable. The Eskimos are slaves of fashion.

I grew up in Minnesota and I tend to be comfortable about ten degrees cooler than most people. 80 degrees is too hot and 60 degrees is nice.

By John Emerson (not verified) on 03 May 2007 #permalink

I know what you mean - they always have to have the new season's mukluks.

By Sandgroper (not verified) on 03 May 2007 #permalink

Sandgroper,

The article you linked to postulated that Neanderthals were not only strong, but fast too - essentially sprinters...

I's think a wide pelvis would have made them very ungainly sprinters?!

A number of Neanderthal's skulls also had a small bony growth in the inner ear, this is also found in people who dive into cold water a lot - so this is physical evidence that they were doing this.

To me this all point to a scenario where I'd imagine them pouncing on seals or walruses instead, stabbing them, and/or wrestling them out of the frigid water. Remember they also had short sturdy legs, large hands and feet, and long trunks - this is the ideal swimming phenotype!

I read something somewhere (for the life of me I can't recall where, I'm pretty bad on references, but then I'm just a dabbler and a pest) that said Neanderthals were built for a lot of leaping around on rugged terrain - not linear running, but leaping sideways and backwards and forwards on steep rocky ground.

Yeah, I don't see them running 400 m with the fluid athletic grace of Cathy Freeman or the late Flo Jo hurling herself linearly through 100 m, female hips notwithstanding.

I've seen reference to that ear thing they had, but have never seen anyone come up with an explanation for it before.

By Sandgroper (not verified) on 03 May 2007 #permalink

Check out this article on Diver's Ear, which lends support to the association of exostosis of the external auditory canal and diving into cold water.

All the great sprinters, male or female tend to have narrow or very narrow hips, including Flo Jo.

In fact the only 100M sprinter I can think of that wasn't like this was Scottish 1980 Gold medal winner Allan Wells, who bucked the trend somewhat.

Frustratingly, I can't find any numbers on pelvic measurements for athletes. Japanese researchers have found a correlation between higher lean muscle mass, lower body fat % and relative success in female heptathletes (no real surprise). Sprinters have high upper body muscle mass including strong shoulder development, relatively thick waists due to strong development of the abdominal muscles, and low body fat %, which on women would translate into low fat on the hips - this could reinforce visual impression that female sprinters are narrow-hipped, but I don't know what measurements of pelvis width would show. They don't seem to have any more difficulty birthing than anyone else.

If anyone knows where I can find some numbers on bone measurements in athletes I'd be gratefu.

By Sandgroper (not verified) on 04 May 2007 #permalink

OK, I'm not a science guy. I stumbled upon gnxp right around the time everyone was guessing where the "living Neandertals" were located. Really exciting stuff. A year goes by, and nothing. I thought maybe Cochran and company are doing genetic tests on the "lost" band of 100% Neandertals to back up their claim, but now I'm guessing there really is no Jay Leno worthy announcement. Bummer.

Paabo is still doing his thing with the genome - it takes years.

And Erik Trinkaus is still publishing about interbreeding.

The evidence of introgression was exciting.

My guess for the 'lost Neanderthals' is the Welsh, if we're playing that game. Or Jay Leno. No, the chin is all wrong.

By Sandgroper (not verified) on 05 May 2007 #permalink

A question I would love to know the answer to is why Neanderthal women seem to have suffered the same kinds of injuries as the men.

With reference to the Grandmother Hypothesis post, it seems Neanderthals didn't live long enough for the kids to know their grandparents (true or not?), so if the women went big game hunting with the men, who stayed home and looked after the kids? Neanderthals took as long to grow up as H. saps.

Or if the injuries were not hunting injuries, what were they? They don't seem like fighting injuries - broken bones and such, not heads bashed in.

By Sandgroper (not verified) on 05 May 2007 #permalink