According to recent genetic research, it seems that the male chromosome of most of the non-African world came out of Africa maybe 50k years ago, then spent several tens of thousands of years in northern latitudes before spreading over the earth. Our brain is made up of many things, but omega-3 lipids are obviously crucial. It's easy to see how people on the shores of Lake Tanganyika got omega-3's - fish. But, where did they get them on the steppes of northern Europe/Asia? I'm wondering if maybe that's why it took so long for northern Eurasians to conquer the planet - that they had to find a much more efficient way of producing or conserving those essential brain lipids than was needed in Africa. So, here's the question: where do modern people who rely totally upon northern non-fish food sources get their birthright of omega-3's for their brains? Laplanders and a few northern Siberian tribes are about all that's left of the northern 'Palaeolithic' diet. I'd appreciate references.