Human populations : diversity and adaptation
As so much of human history is the history of population migrations, all the world's populations interact at the genetic, morphological and cultural levels. In the nineteenth century, populations were placed on a scale from 'primitive' to 'advanced'. With the impact of Darwinism, processes of natural selection were sought that might be capable of explaining physical inter-population differences. Continued study of population genetics has led to the discovery of the selective advantages of particular genes, together with an understanding that not all genetic differences are the product of natural selection, but that neutral processes operate as well. This is an exploration of aspects of human diversity and the ways in which human populations adapt to their environments.
SUMMARY ::: ::: The conditions of stability for a set of alleles under selection are discussed with special reference to the cases where homozygotes are disadvantageous. The concrete example of alleles which produce different haemoglobins is considered.