On Sun, 7 Nov 2010, Keith Hudson wrote: Wherever intensive manual agriculture was practised around the world, > the nutritionally poor diet (carbohydrate-rich, protein-poor) resulted in > short and underweight individuals compared with man in Neolithic times. This > was due to epigenetic effects on the normal developmental genes in the > embryo. When diets began to improve during industrial times -- from about 200 > years ago in Europe -- epigenetic control began relaxing in stages and, > within about five or six generations, the size and weight of babies improved > each generation -- and, of course, in the adult. In the UK, for example, > upper middle-class individuals had recovered full Neolithic size and weight > about three generations ago while most of the population are only just about > reaching it now. (Americans got there sooner. Even as late as the 1940s when > American soldiers were arriving in England preparatory to the invasion of > Germany-occupied Europe, it was noticed that on average they were several > inches taller and many pounds heavier than English soldiers.) The full > recovery of normal weight and size appears to take about five or six > generations of a nutritionally adequate diet -- each new generation stepping > upwards, as it were, (roughly a gain of about a quarter-pound in birth weight > each successive generation). The same effect is now occurring in parts of > Asia because they are now weaning themselves away from an almost exclusively > rice/millet/wheat diet. The Japanese are still about two generations away > from full epigenetic recovery while other Asians such as the Vietnamese or > the Chinese are still distinctly small and are still several generations away > from full Neolithic stature. (The Dalits of India are still probably a couple > of centuries away from full stature -- if indeed, they ever receive an > adequate diet.) >
I'm afraid this doesn't quite work. I believe the real reason for north americans being larger is the large amount of dairy they consume, but I'm not sure. At any rate, the problem with your thesis is that both europeans and asians arriving in north america, who adopt the north american diet, have children who grow to the north american norm, in the first generation; and this has been true for the last half century, which is the period in which north america has been well stocked with nutritious food. (I'll leave aside the subject of the rise of junk food, and the current decline in nutritional habits.) -Pete _______________________________________________ Futurework mailing list [email protected] https://lists.uwaterloo.ca/mailman/listinfo/futurework
