A massive new review, Shades of complexity: New perspectives on the evolution and genetic architecture of human skin, pointed me to another paper on South Asian skin color, The influences of genes, the environment, and social factors on the evolution of skin color diversity in India. I was very interested because South Asians have been telling me about complexion my whole life. Usually, it is to suggest that their group is lighter than some other group. So I thought it would be interesting to post some data.
The figure at the top shows melanin indexes for a host of populations. The lower the value, the lighter the skin. So you see that Irish samples above have a melanin index of 26.5, while Italians have one of 31. East Asians in Canada have a melanin index of 38. Predominantly African ancestry populations have melanin indices >50, while the very dark Melanesian people of the Solomon Islands have a melanin index of about 90.
I’ve collected the Indian data from the paper:
|Group||N||Mean Melanin Index||Range||stdev|
|Bihar Scheduled Castes||80||59.9||46.2-78.9||7.8|
And here’s a figure for Andhra Pradesh:
Finally, 42% of the skin color variation in the data can be explained by caste.
More data, from UP: