A quote from: http://www.nature.com/ng/index.html [In an advance publication article in 'Nature Genetics'] Sarah Tishkoff and colleagues report that lactase persistence due to variation upstream of the gene encoding lactase-phlorizin hydrolase (LPH) has arisen independently in Africans and Europeans. Their results confirm the strong selective pressure of adult milk consumption in human evolution. Nature Genetics Published online: 10 December 2006; doi:10.1038/ng1946 Convergent adaptation of human lactase persistence in Africa and Europe Sarah A Tishkoff et. al. [very long author list omitted] Abstract A SNP in the gene encoding lactase (LCT) (C/T-13910) is associated with the ability to digest milk as adults (lactase persistence) in Europeans, but the genetic basis of lactase persistence in Africans was previously unknown. We conducted a genotype-phenotype association study in 470 Tanzanians, Kenyans and Sudanese and identified three SNPs (G/C-14010, T/G-13915 and C/G-13907) that are associated with lactase persistence and that have derived alleles that significantly enhance transcription from the LCT promoter in vitro. These SNPs originated on different haplotype backgrounds from the European C/T-13910 SNP and from each other. Genotyping across a 3-Mb region demonstrated haplotype homozygosity extending >2.0 Mb on chromosomes carrying C-14010, consistent with a selective sweep over the past approx7,000 years. These data provide a marked example of convergent evolution due to strong selective pressure resulting from shared cultural traits?animal domestication and adult milk consumption. Abstract online at (also full-text access at): http://www.nature.com/ng/journal/vaop/ncurrent/abs/ng1946.html Related online news story, 'Science' magazine: Milk Tolerance Evolved More Than Once By Ann Gibbons ScienceNOW Daily News 11 December 2006 Free online access (for a limited time) at: http://sciencenow.sciencemag.org/cgi/content/full/2006/1211/1 1st paragraph of Science news story: Milk may do a body good for some, but for half of the world's adults, it causes cramps and diarrhea. Now, a new study indicates that the ability to digest milk arose more than once in humans descended from cattle herders--a finding that sheds light on how culture can have a rapid and dramatic effect on our genome. Tom Billings