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Wednesday, March 14, 2007

A hairy debate over our Stone Age moms

Why aren?t humans furry? We barely know the answer to this question. But psychologist Judith Rich-Harris believes that she has a theory that could explain why we bare more skin than our primate cousins.

She believes that during the Stone Age our ancestral mothers thought less hairy babies were cuter and therefore abandoned these newborns less often. Over time, this selection process made us less furry.

The journal Medical Hypotheses has announced that Rich-Harris has won the 2006 David Horrobin Prize for her theory. A press release sums up her theory:


I?m not totally persuaded by this idea. Are bald men more attractive than those with hair? Are Chihuahuas the cutest dogs? Some people would say no. So why would Stone Age moms see furless babies as more attractive and worth caring for?

Roxanne Khamsi, online reporter (Image: Andrea)
Perhaps it was not attractiveness but something more basic in maternal instinct. In modern humans, a mother will be more protective of their child if that child is seen to have a deficit from birth in a physical handicap or other similar limitations. Perhaps our primitive ancestors had a similar reaction to a slightly less hairy child. Remember the old saying, ?Only a face a mother could love.? Perhaps this simple maternal concern is all that was needed.

I don't necessarily agree with the theory, but simply because we don't find bald men attractive doesn't mean naked babies wouldn't be better off. Hairlessness in itself is not the attractor, it's the visual cue of youth. In chimps this is seen as a light-coloured face that only infants have. In humans, it's the shape of head, size of eyes and so on that are "cute" in babies but would look weird on adults. Baldness in men on the other hand, is related to secondary and tertiary sexual characteristics, so not all baldness is equal.
By Anonymous Anonymous on March 14, 2007 1:20 PM  
They are handing out awards for reciting basic selection theories? Good gravy!
It could even be due to a trait related to one actually selected for, such as adornment...the more attractive mates were those with obvious adornment, like necklaces and bracelets, and hairier primates were more troubled by such baubles, always getting hairs painfully pinched and pulled out - and so wore such items less (and were not selected for because they weren't wearing the latest fashions). Once we enter the realm of "what were they thinking" we may as well admit that we are idly playing Pin the Tail on the Donkey and not doing science. How would we test ANY of these theories? Stephen Colbert would tell us that we test them by determining which ones that win prizes - and those must be right. Perhaps the less hairy were less agressive, and therefore seen as less likely to rape? Who knows?
By Anonymous Anonymous on March 14, 2007 7:01 PM  
Various thoughts come to mind. The first being that as we moved out of the jungles and the safety they provided, those with less hair were able to run further and sweat more efficiently. More comfortable in a hot climate and for one, and better to avoid being eaten.

More importantly, they would also be better long distance hunters. It's thought prey were often tracked and chased until they simply collapsed, a technique still in use today. Hunters with less hair would be able to track prey for longer, becoming better providers, hence more attractive mates. After many generations of balding, sweaty, but well fed Alpha males, less hair could instinctively become more attractive to females, or certainly be instilled as such from a young age. The remaining hair on our heads could even be attributed to something as simple as wild hairstyles becoming a popular new way to attract females.

Frankly, I find baby chimps way up there on the cute scale with human babies! A mothers instincts are amazingly strong no matter how their baby looks. I find it much more likely to be related in someway to success as a provider and mate.

Alex (at realitysedge.googlemail.com)
By Anonymous Anonymous on March 15, 2007 1:09 AM  
Sure, we can think up many different hypotheses about why humans aren't hairy.
But that's not the main point of either the press release,
or the journal article
http://xchar.home.att.net/n2a/medhyp.htm .
The point is that a third mechanism, in addition to Darwin's adaptive selection and sexual selection,
may drive evolutionary change, namely selection by parents.
This mechanism could yield relatively rapid changes. And in humans it could
be a way for cultural factors to influence evolution and diversification.
By Anonymous Peter Linn on March 15, 2007 6:38 AM  
I don't disagree with the theory, but how exactly would maternal selection work? Did mothers kill or abandon the hairier babies? Would the "preferred" child get six years of care instead of, say, five?

Also, "maternal preference selection" seems to be just a means. I doubt mothers consciously planned to advance the species or her lineage by selection. Is it supposed to have been a side effect of some mental construct, or was it a manifestation of a deeper selective force, such as promoting neoteny? The report here leaves much to consider.
By Anonymous Anonymous on March 16, 2007 11:06 AM  
The Aquatic Ape Theory makes more sense.
By Anonymous Anonymous on March 16, 2007 2:14 PM  
maybe it was just the trend of the time...hairless babies: a must have rather than the reg fur ones...
personally I think babies would be more cute with fur...like baby ewoks...:)
By Anonymous Anonymous on March 16, 2007 4:49 PM  
I read somewhere that a lack of human hair evolved or was selected for because less hair meant less parasites. annoying and damaging parasites had nowhere to hide,
and/or were more easily located and removed, therefore giving humans with less hair a slight survival advantage in certain locations
By Anonymous Anonymous on March 18, 2007 6:03 AM  
I hesitate to bring this up, since it will probably start a religious flame war, but:

Does anyone else think it is interesting and/or significant that the Bible closely links the beginning of the nakedness taboo with the wearing of clothing? This would argue for a non-utilitarian origin for clothing, due to an emotional/spiritual/social sensitivity to being "naked" that came about very early in the history of humans. Once public nakedness became taboo, it might have made private nakedness that much more desirable -- the more naked, the better.
By Anonymous Anonymous on March 20, 2007 3:27 PM  
Surely clothes are humans replacement for fur. Therefore I think that the loss of fur must have corresponded directly with the use of clothes. The advantage of fur are that it keeps you warm and the disadvantage is that parasites can live in it. With clothes to keep you warm, there are no advantages to having fur.
When does Rich-Harris propose the evolution of hairless babies occurred? Her theory is intriguing, but as many of the other posters are saying, the hairless baby phenomena was probably multi-factorial. Could climate have factored in? Disease (i.e. can ticks live easier in fur?) Have any other species experienced a similar hairless revolution? What were the reasons behind it?
I have a theory! What if we didn't evolve? Now give me my award!

Unfortunately I've lost all creditability in evolution. Not because of the theory itself, but the scientists making claims that turn out to be fake, or just plain wrong. How do I know that the next big "discovery" is just a scam of not. I find that there are just too many scientists making way to many excuses. If evolution (Macro Evolution) was not just a theory, but a fact, then how could anyone argue that it isn't?

Fact: Rome is in Italy
Fact: 2 + 2 = 4
Fact: I'm typing in English

You can't argue against those claims at all! But bring up evolution, and you got one big fight in your hands.

Fact: Evolution is not a Fact, just a theory.
Most semi-aquatic mammals are not naked, but furless + fat mammals all appear to spend a lot of time in the water. AAT, the waterside theory of human evolution, is still often misrepresented. It says that after the human/chimp divergence c.5 Ma, the lineage leading to us was a lot more dependent on water than the chimp lineage. The general view is clear (human relatives/ancestors along African & Indian Ocean shores, eg, reaching Java & Flores, & venturing inland along rivers etc.), but the details are still discussed. For recent views, please google ?aquarboreal? or have a look at http://groups.yahoo.com/group/AAT or http://users.ugent.be/~mvaneech/outthere.htm
I think it has to do with temperature back then, more fur, the more you where warm.
in the pass we have gotten less hairy, because there is no need for all that fur since he have other ways to be warm. ..
its not like they had clothes.
we do, so we don't need alot of hair to keep us warm.

By Anonymous Anonymous on January 10, 2009 2:30 AM  
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