Thursday, August 30, 2007

Even your moma thinks you're ugly

Every year, Medical Hypotheses, an Eselvier publication, gives out a prize to honour those who think outside of the box. In 2006 the prize was given for this paper "Parental selection: a third selection process in the evolution of human hairlessness and skin color". Now the first part of that title actually makes sense, parental selection undoubtedly plays a role in evolution, including human evolution. Often in birds, parents will favor one of the offspring and let the others die. It's all a matter of opportunity cost. The metabolic cost of making a second egg, while high for the female, is still outweighed by the potential cost of losing one egg and not being able to reproduce for one season, especially if life expectancy is short. In other words, two birds in the nest is better than none in the bush. For birds, this selection may depend on cracking out of the egg a few minutes earlier, or being noisier, or having a bigger redder beak. In humans the situation is quite different. For one, twin births are relatively rare so there is no competition for milk. This means the most likely mechanism of parental selection would probably be infanticide. It is not hard to imagine that this could happen on the basis of the sex of the baby, or perhaps if there is a malformation or mental retardation. But the authors go further, much further, and they crossed the line, in fact they are so far from the line, they can't even see the line. They argue that babies had to look cute otherwise their mothers would abandon them, so they became all pink and lost their hair, so has to not be confused with Neanderthals. WHAAT? First of all, if anything, genes that would make mothers find their baby attractive no matter what are more likely to be positively selected than genes which makes them choosy. For eutherian mammals, the maternal investment leading to birth is huge, they wouldn't just throw the baby with the bathwater because he is too hairy, or not pink enough. In fact the stupidity is even greater, because if you assume that our ancestors started out hairy, then the difference in hair compared to Neanderthals does not help to discriminate the two. I mean you just have to look at the face, that's enough to differentiate them. Some people even argue that the two species might have interbred. That also seems odd to me, I mean when I see a monkey, the last thing I want is to have sex with it. I don't know about you. Plus, imagine how technically difficult that would be, first you would have to catch it in the trees. Anyways, there are definitely better theories for hairlessness such as having less parasites, especially since we humans are such poor social groomers... So I'll put that theory in the same garbage bin as the we're hairless because we had an "aquatic ape" phase bullshit.


5 comments:

rob said...

The aquatic ape theory! I had almost forgot about it. I saw Elaine Morgan speak at SFU when I was in undergrad. Good speaker, crazy idea with no real evidence. But I guess she's sold more books than me, that's for sure. The link that you posted has another link on it to:
http://www.aquaticape.org/
which basically negates any point in having a bayblab post on the aquatic ape. It's worth a quick skim for a read if you haven't heard of the aquatic ape.

"the Dude" said...

What is the most aquatic ape:

kamel said...

A Sea Monkey?

Bayman said...

Hey I don't know exactly what Neanderthals looked like with flesh and skin and hair and all, but I bet some of them might have been quite a bit more attractive than monkeys...

Plus, maybe we hadn't yet evolved neurological or cultural mechanisms to discriminate between ourselves and other hominids.

I often wonder if there hasn't been a lot more interspecies breeding than humans would find morally palatable during the course of natural history and whether this might explain a lot of the biological diversity that has been generated... I'm also willing to bet someone who knows something about evolution could cite some obvious evidence to prove me wrong on this...

aquape said...

AAT, the waterside theory of human evolution, is often misrepresentedbut essentially 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