One day, in a Milanese bookshop, I had some sort of illumination: I was holding in my hand a book in Italian and was thinking that its title was kind of summarizing in three words my main interests… However, my Italian still being a bit rough (in particular for genetics-related publications) I ordered online the English translation and received a few days later at home Luigi-Luca Cavalli-Sforza's book: "Genes, peoples and languages"[1] that Jared Diamond had found "doubly interesting: as a window into the history of all of us, and as a window into the mind of a remarkable scientist".
Until this particular day, I would have been embarrassed to give much details on L. Cavalli Sforza and his work. I was only remembering his surname because it was reminding me of the Sforza family, Dukes of Milan who built a massive castle that is still proudly standing in the city centre. My interest in the genetic side of history and genealogy was pretty recent[2]. But I had convinced myself it was time to learn, and this book was a fairly good way to start.
Cavalli Sforza is an Italian population geneticist, Professor (now Emeritus) at Stanford since 1970. "Genes, peoples and languages" could be described as an accessible summary of his work. Accessible, because one doesn't need any particular knowledge of genetics and DNA to understand his main lines of thought and his explanations.
I will try in the next weeks to summarize the main ideas developed in this book and point out the interesting debates it contributes to.
Aware of the ideological potential of genetics when used for other purposes, CS starts by reminding his readers that the main genetic differences are between individuals and not between population or "races". Genetics is instrumental in shaping us, but so to are our cultural, social and physical environments. So, before coming back to the main objective of his research and his book -providing a clear picture of the expansions and migrations out of Africa- CS feels the duty to discuss the scientific basis for racism to clarify his thoughts on the matter once for all.
He notes that most people do not distinguish between biological and cultural heredity. Genetically determined traits are very stable over time, unlike socially determined or learned behaviours which can change very rapidly. He then recalls why it is partially understandable that in the past centuries, since only visible traits could be studied, people could imagine that pure races existed. But with the drastic improvement in scientific knowledge he describes as absurd the persistence of this belief. To achieve even partial "purity" (a genetic homogeneity that is never achieved spontaneously in any population) it would require at least twenty generations of "inbreeding" (brother-sister or parent-children matings repeated many times). Such inbreeding would have severe consequences for the health and fertility of the children.
Our perception of racial purity is therefore truly superficial, limited to body surface, which is determined by climate. Furthermore, our poor understanding of the hereditary mechanism of familiar physical characteristics (height, skin, hair and eye color) is due to their interaction with non-genetic, environmental factors.
TO BE FOLLOWED
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