Monday, February 27, 2006

Blondes had a selective advantage 10,000 years ago?


I read a recent article in the Times suggesting the diversity of hair colour arose some 10,000 years ago and that blonde hair was a selective advantage for women. I have gone to the original scientific publication (Evolution and Human Behavior, Volume 27, Issue 2, Pages 85-168, March 2006) because I was intrigued at how they measured that this trait arose prior to 10,000 years ago. Essentially, it seems that sexual selection must have played a role in Europe as humans moved further north 35,000 years ago. The women became more reliant on the men for food and men having to hunt further away from home were more likely to die probably resulting in a higher proportion of females competing for the males attention, thus colourful hair being an advantageous attention-seeking trait.

It turns out that the molecular data gives a rather different date for the origin of the hair colour: "Harding et al. (2000) have investigated this evolutionary scenario and found that the time to the most recent common ancestral hair color would be about a million years, with the redhead alleles alone being approximately 80,000 years old. Templeton (2002) has come to a similar conclusion: If the cause were relaxation of selection, the current level of hair-color diversity would have taken 850,000 years to develop."

The more rapid evolution suggested by the anthropologist Frost is a result of positive selection (rather than relaxation of selection being the cause for polymorphism in hair colour).

4 comments:

Anonymous said...

Blonde ditsy women are evolutionarily advantaged.

Let me explain why.

We obsess - over everything. It is the way we function. Obviously there must be some correlation between the level of intelligence and the level of obsession and therfore relationship success rates. Intelligent brunette women - we are talking ability to think logically- will have the ability to determine and form every possible scenario for her boyfriends alloofness. Clearly the larger her brain capacity the more scenarios she will come up with, resulting in her obsession to rise logarthimically, along with her unhappiness. Since there is a known link between intelligence and logic. She will come up with all logical explanations based on the information she has. This partiular case inpoint shows lack of information increases obsession and decreases happiness. We could postulate therefore that increased information would decrease obsession and correspondingly increase happiness - but I digress.

Back to the point, blonde women - who potentially don't have the same capacity for protracted logical thinking - will give up at a much earlier stage in the obsession over her boyfriends alloofness (lower intelligence - > lower obsession rates) - will eventually forget why she is obsessing and will give up and be happily ignorant (lower obsession rates -> increased happiness) and less likely to cry herself to sleep. The blonde ditsy girl will be more happy and therefore less likely to take the logical next step of walking away from this relationship.

Conclusion, blonde women - remain in relationships- procreate - and create more ditsy women. It is therefore not simply that the fittest survive , it is that the fittest procreate!

Blonde women of the world I salute you - go forth be happy and reproduce.

Anonymous said...

Blonde ditsy women are evolutionarily advantaged.

Let me explain why.

We obsess - over everything. It is the way we function. Obviously there must be some correlation between the level of intelligence and the level of obsession and therfore relationship success rates. Intelligent brunette women - we are talking ability to think logically- will have the ability to determine and form every possible scenario for her boyfriends alloofness. Clearly the larger her brain capacity the more scenarios she will come up with, resulting in her obsession to rise logarthimically, along with her unhappiness. Since there is a known link between intelligence and logic. She will come up with all logical explanations based on the information she has. This partiular case inpoint shows lack of information increases obsession and decreases happiness. We could postulate therefore that increased information would decrease obsession and correspondingly increase happiness - but I digress.

Back to the point, blonde women - who potentially don't have the same capacity for protracted logical thinking - will give up at a much earlier stage in the obsession over her boyfriends alloofness (lower intelligence - > lower obsession rates) - will eventually forget why she is obsessing and will give up and be happily ignorant (lower obsession rates -> increased happiness) and less likely to cry herself to sleep. The blonde ditsy girl will be more happy and therefore less likely to take the logical next step of walking away from this relationship.

Conclusion, blonde women - remain in relationships- procreate - and create more ditsy women. It is therefore not simply that the fittest survive , it is that the fittest procreate!

Blonde women of the world I salute you - go forth be happy and reproduce.

kristl smith tyler said...

Two reasons the conclusions made by Anonymous don't work:

1) most American blondes are born brunette. If you count 100 blondes you will be lucky to find one who is natural (unless you like in Minnesota)

2) Staying in a relationship does not help you procreate - though it may help you raise them to their own age of procreation

In order to make the second point work you would have to separate it from the first - bc ditsy-ness and cheating would be largely modern concepts and needing a man for your children to make it to adulthood is a fairly less modern concept.

kristl smith tyler said...

To the Author -

I have often wondered why I always think it looks nice when people get highlights- regardless of their original haircolor or the actual color of the highlights. For example, if a dark brunette gets highlights, her highlights might be red or caramel and yet it still strikes me as attractive.

I wondered if this might be related to the best seasons to be pregnant and give birth. We know animals mate in spring. Do the sun's highlights in early summer make women more attractive for mating?

If human's highlights are strongest at the end of the summer, and thus she is more attractive then, she will give birth in February. This would be true for any hot/cold season cycle. Regardless of where you lived, the end of the hot season might be an ideal time to mate.

I don't know if this holds water. What do you think?

Disqus for Evo-Karma