Ancestors of Inuits came to polar regions less then 10 thousand years ago. Yet even during this short from evolutionary perspective time frame they got a mutati

Ancestors of Inuits came to polar regions less then 10 thousand years ago. Yet even during this short from evolutionary perspective time frame they got a mutation that inhibited ketosis. Even outside the polar regions to places where fruits and vegetables where not available or were very limited people came relatively recently. For example, in Mongolia it happened about 20 thousands years ago. Moreover, human population there in any substantial numbers appeared less than 10K years after domestication of animals and access to their milk. In Mongolia people living in traditional ways drink a lot of fermented horse and camel milk getting enough calories from carbohydrates to avoid a permanent keto state. So a permanent keto state from evolutionary perspective was never sustainable.