Excavation of a southern French burial site from about 3,000 BCE shows that the modern humans who expanded into the area from the Mediterranean lived in patrilocal communities (where couples live in the man's settlement), and did not have the genetic mutation that allowed later Europeans to digest fresh milk.
     Scientists analysed DNA extracted from the bones of 53 people buried in Cave 1 of the Treilles, located in the Grands Causses region at Saint-Jean-et-Saint-Paul, Aveyron (south of the Viaduc de Milau) in France. They were able to get useful information from 29 of those samples; 22 men, 2 women and 5 for whom it was impossible to determine sex. Most appeared to be closely related, with two having a 99.9979% probability of being father and son and two others having a 99.9985% probability of being siblings.
     Researchers deduce that the peoples in this region of France were of a genetic type more closely related to Basque and Spanish populations than current western European populations. They were also more closely related to peoples in Cyprus, Portugal, Turkey, Italy and Lebanon. None carried the gene for lactase persistence that is believed to have first evolved around 5,500 BCE in central Europe, and which allowed humans to drink fresh milk after they are weaned.
     The absence of the genetic variation probably shows that the Treilles people came from agricultural-pastoral Mediterranean cultures that drank fermented milk, and had an economy based on sheep and goat farming.

Edited from PNAS (2 May 2011), Science Fair (31 May 2011)