Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past

by David Reich

Is it possible that the steppe people had picked up the plague and built up an immunity to it, and then transmitted it to the immunologically susceptible central European farmers, causing their numbers to collapse and thereby clearing the way for the Corded Ware culture expansion? This would be a great irony. One of the most important reasons for the collapse of Native American populations after 1492 was infectious diseases spread by Europeans who plausibly had built up some immunity to these diseases after thousands of years of exposure as a result of living in close proximity to their farm animals. But Native Americans, who by and large lacked domesticated animals, likely had much less resistance to them. Was it possible that, in a similar way, northern European farmers after five thousand years ago were decimated by plagues brought from the east, paving the way for the spread of steppe ancestry through Europe?