A study led by Harvard Medical School and published in Nature has analyzed 230 genome samples from ancient Europeans. Thanks to these analyzes, among which there were fifteen samples of genetic material collected in the El Mirador cave, in Atapuerca, the human genes that changed during the Neolithic age, when the transition from hunting to agriculture took place, have been identified. So far, researchers have identified changes in 12 genes related to traits such as skin and eye color, lactose tolerance, and height. And yes, by then, the inhabitants of the south were already shorter than those of the north.
Using samples from 8,000 years of European prehistory, the study authors have created a portrait of the evolution of the continent’s inhabitants. The variations found correspond to genes associated with height, the ability to digest lactose in adulthood, the metabolism of fatty acids, vitamin D levels, skin pigmentation or the blue color of the eyes, among others, and explain the adaptation of Europeans to the establishment of agriculture in high latitudes.
For example, the clear pigmentation of the skin would have been necessary to supply vitamin D in agricultural diets, genes related to celiac disease could have advantages to avoid vitamin deficiencies in this new type of diet, and immunity genes probably reflected adaptations to pathogens that come from contact with domestic animals.
Another idea that emerges from the study is that the first European farmers came from ancient Anatolia, in present-day Turkey. It also establishes that today’s Europeans are the product of three major population substrates: Mesolithic hunter-gatherers, Neolithic farmers, and the population of the steppes that arrived in the Bronze Age.
In the Iberian Peninsula the group of Neolithic farmers predominates more, less the Mesolithic group than in northern Europe and also less the steppe group than in the center and north of the continent. As José María Bermúdez de Castro, a researcher at the National Center for Research on Human Evolution (CENIEH) and co-author of the study, explained to the SINC agency, the differences between northern and southern Europe have an environmental component due to factors such as diet and light, but they are also based on the fact that migrations from Southwest Asia occurred at different times and by different tribes.
However, according to this researcher, the common mesolithic base is also very important. Hence the great similarities between all Europeans, who have only received occasional influences from other peoples from Africa and Asia in much more recent dates . Among the differences, it is necessary to highlight the stature: the inhabitants of the north, who descend to a greater extent from the tribes of the Eurasian steppe, are taller and those of the south are shorter.
Equally remarkable is the fact that 4,000 years ago, Europeans acquired the ability to digest milk in adulthood, a change marked by the appearance of a gene related to the persistence of the enzyme lactase , according to the study. Today this mutation that allows the elderly to drink and digest milk is present in 100% of Europeans from the north of the continent and it presents a great advantage for survival.
