Substack cometh, and lo it is good. (Pricing)

Bah bah black sheep and balancing selection?

Secret Of Scottish Sheep Evolution Discovered:

…gene and one copy of the light gene are quite large and also have quite high reproductive success. Sheep with two copies of the dark gene are larger still, but have poor reproductive success. Sheep with two copies of the light gene are small, but still have quite high reproductive success. This means that the two types of dark sheep although indistinguishable visually, vary in Darwinian fitness.

The paper will be “A Localised Negative Genetic Correlation Constrains Microevolution of Coat Colour in Wild Sheep” in Science (not on the site yet). I wish I had some numbers to put on this…because I want to know the reproductive fitness of heterozygote black sheep vs. white sheep (ergo, the question mark after “balancing selection”). In any case, I wonder how it might apply to human pigmentation genes & selection. Consider the KITLG allele which results in dominance effects for light skin but recessive effects for light hair, and was subject to recent selection in Europeans. Or the affect of an OCA2 allele on eye & skin color.

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