Staccato
06-09-2013, 11:12 PM
What factors resulted in this? Is it simply only a result of the climate?
This theory below by Peter Frost always interested me, but does it have any credence?
European hair and eye color: A case of frequency-dependent sexual selection?
http://www.ceacb.ucl.ac.uk/cultureclub/files/CC2006-03-07_Frost.pdf
Abstract
Human hair and eye color is unusually diverse in northern and eastern Europe. The many alleles
involved (at least seven for hair color) and their independent origin over a short span of evolutionary
time indicate some kind of selection. Sexual selection is particularly indicated because it is known to
favor color traits and color polymorphisms. In addition, hair and eye color is most diverse in what used
to be, when first peopled by hunter-gatherers, a unique ecozone of low-latitude continental tundra.
This type of environment skews the operational sex ratio (OSR) of hunter-gatherers toward a male
shortage in two ways: (1) men have to hunt highly mobile and spatially concentrated herbivores over
longer distances, with no alternate food sources in case of failure, the result being more deaths among
young men; (2) women have fewer opportunities for food gathering and thus require more male
provisioning, the result being less polygyny. These two factors combine to leave more women than
men unmated at any one time. Such an OSR imbalance would have increased the pressures of sexual
selection on early European women, one possible outcome being an unusual complex of color traits:
hair- and eye-color diversity and, possibly, extreme skin depigmentation.
So essentially, according to Frost, North European women evolved blonde hair and blue eyes at the end of the Ice Age to make them stand out from their rivals at a time of fierce competition for scarce males. The pressure of sexual selection was therefore on the female sex. They were the ones who had to compete for mates.
This theory below by Peter Frost always interested me, but does it have any credence?
European hair and eye color: A case of frequency-dependent sexual selection?
http://www.ceacb.ucl.ac.uk/cultureclub/files/CC2006-03-07_Frost.pdf
Abstract
Human hair and eye color is unusually diverse in northern and eastern Europe. The many alleles
involved (at least seven for hair color) and their independent origin over a short span of evolutionary
time indicate some kind of selection. Sexual selection is particularly indicated because it is known to
favor color traits and color polymorphisms. In addition, hair and eye color is most diverse in what used
to be, when first peopled by hunter-gatherers, a unique ecozone of low-latitude continental tundra.
This type of environment skews the operational sex ratio (OSR) of hunter-gatherers toward a male
shortage in two ways: (1) men have to hunt highly mobile and spatially concentrated herbivores over
longer distances, with no alternate food sources in case of failure, the result being more deaths among
young men; (2) women have fewer opportunities for food gathering and thus require more male
provisioning, the result being less polygyny. These two factors combine to leave more women than
men unmated at any one time. Such an OSR imbalance would have increased the pressures of sexual
selection on early European women, one possible outcome being an unusual complex of color traits:
hair- and eye-color diversity and, possibly, extreme skin depigmentation.
So essentially, according to Frost, North European women evolved blonde hair and blue eyes at the end of the Ice Age to make them stand out from their rivals at a time of fierce competition for scarce males. The pressure of sexual selection was therefore on the female sex. They were the ones who had to compete for mates.