I have several maps today. Still intrigued by the lack of the supposed lactase persistence allele (LCT 13910-T) in the 7 European Neolithic skeletons, I was trying to find a map of the frequency of that allele across Europe (or the world). This was mainly an internet search, and I only looked at a few of the published papers. This is what I found:
This one (above) shows the percentage of people who are lactose intolerant (however that was measured??)
This one shows pretty much the same thing, but inverse - those who are lactose tolerant -- here again, highest in Northwest Europe and not all that high in central, eastern, and southeastern europe (where those neolithic skelonts were found)
This one shows the lactose absorption across Europe. This is from the website of Karin Haack, a PhD student interested in "Exploring human diet in prehistory through the genetic trait of lactase persistence". In referring to this map, she says:
"Looking at the map of percentages for lactose absorption in Europe one can see a distinct cline from the north-west to the south east. This is very interesting for the following reason: animals were domesticated in the Near East around 10,000 years ago and then subsequently spread over Europe till animal domesticates reached the British Isles around 6,000 years ago. One would therefore expect populations in the Near East to have highest percentages of lactose absorption and populations in north-western Europe to have lowest percentages of lactose absorption, if lactase persistence was selected for with the domestication of animals and development of dairying. But percentages for lactose absorption are highest in those regions where domesticated animals arrived last in Europe not where animal where domesticated. Therefore the selection for lactase persistence should be a north-western European event which essentially means that there should be multiple origins for lactase persistence all over the world since high percentages occur elsewhere in the world. An indication that there must be multiple origins for lactase persistence is given by my revision of genetic data generated by Hollox et al. (2001)."
Well anyway, one of my points for this long post is that the absence of the LCT 13910 allele in the Neolithic skeletons may not be inconsistent with the relatively high frequency of lactose intolerance in many parts of Europe. There are still many unanswered questions, for me at least. Do we know the allele frequency of 13910-T in different parts of Europe today ?(we probably do) and to what extent is that the causative allele (any physiological evidence?), and finally, to what extent is the phenotype plastic?