The history behind lactose intolerance, revealed.
The study, published August 28, explains how Europeans evolved to drink milk as adults (lactase persistence). The findings suggest that lactase persistence began around 7,500 years ago, and further confirm that the ability to drink milk as an adult has been a coevolutionary process between genetics and agricultural development.
Yuval Itan and colleagues develop a simulation model of the spread of lactase persistence, dairying, and farmers in Europe, combining genetic and archaeological data using newly developed statistical approaches. They study a single genetic variant strongly associated with lactase persistence, ?13,910*T, which they find to have been favored by natural selection within the past 10,000 years. By matching this with the historical timeline of humans’ beginning to drink fresh milk due to animal domestication, the researchers were able to map this lactase persistence.
The group infers that lactase persistence/dairying coevolution began around 7,500 years ago between the central Balkans and central Europe. However, they also determine that populations inhabiting higher latitudes didn’t progress towards adult milk consumption any more quickly, despite an increased requirement for dietary vitamin D. The authors note that this work exemplifies the possibility of integrating genetic and archaeological data to address important questions on human evolution.
This study has garnered a wide range of coverage, including:
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