Via Yan Klimentidis' blog.
Yuval Itan et al. A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evolutionary Biology, 2010. Open access PDF.
The authors explore the differences between actual lactase persistence phenotypes, i.e. the real apportions of adults who can digest milk, and the presence of alleles thought to cause this phenotype. They find that in many parts of the world, notably SE Europe, West Asia and most of Africa, the number of actual milk drinkers is often very different than known genetics could predict.
Some striking examples:
- Central Italians: actual LP: 82% - predicted by genetics: 21%
- Afghan Tajiks: actual LP: 18% - predicted: 51%
- Jordanians: actual LP: 76% - predicted: 20%
- Balochis: actual LP: 38% - predicted: 0%
- Wolof (Senegal): actual LP: 51% - predicted: 0%
- Sudanese: actual LP: 88% - predicted: 45%