In a Science article from last year, Ann Gibbons discusses the ancient migrations that can now be traced using DNA analysis:
After World War II, many scholars recoiled from studying migrations, in reaction to the Nazi misuse of history and archaeology. The Nazis had invoked migrations of “foreign” groups to German territory to justify genocide. “The whole field of migration studies was ideologically tainted,” says archaeologist Kristian Kristiansen of the University of Gothenburg in Sweden. Some researchers also resisted the idea that migration helped spread key innovations such as farming, partly because that might imply that certain groups were superior.
Nor did researchers have a reliable method to trace prehistoric migrations. “Most of the archaeological evidence for movement is based on artifacts, but artifacts can be stolen or copied, so they are not a real good proxy for actual human movement,” says archaeologist Doug Price of the University of Wisconsin in Madison, who tracks ancient migration by analyzing isotopes. “When I started doing this in 1990, I thought people were very sedentary and didn’t move around much.”
Today, however, new methods yield more definitive evidence of migration, sparking an explosion of studies. The isotopes Price and others study are specific to local water and food and thus can reveal where people grew up and whether they later migrated. DNA from ancient skeletons and living people offers the “gold standard” in proving who was related to whom.
The new data confirm that humans have always had wanderlust, plus a yen to mix with all manner of strangers. After the first Homo sapiens arose in Africa, several bands walked out of the continent about 60,000 years ago and into the arms of Neandertals and other archaic humans. Today, almost all humans outside Africa carry traces of archaic DNA.
That was just one of many episodes of migration and mixing. The first Europeans came from Africa via the Middle East and settled there about 43,000 years ago. But some of those pioneers, such as a 40,000-year-old individual from Romania, have little connection to today’s Europeans, Reich says.
His team studied DNA from 51 Europeans and Asians who lived 7000 to 45,000 years ago. They found that most of the DNA in living Europeans originated in three major migrations, starting with hunter-gatherers who came from the Middle East as the glaciers retreated 19,000 to 14,000 years ago. In a second migration about 9000 years ago, farmers from northwestern Anatolia, in what is now Greece and Turkey, moved in.
That massive wave of farmers washed across the continent. Ancient DNA records their arrival in Germany, where they are linked with the Linear Pottery culture, 6900 to 7500 years ago. A 7000-year-old woman from Stuttgart, Germany, for example, has the farmers’ genetic signatures, setting her apart from eight hunter-gatherers who lived just 1000 years earlier in Luxembourg and Sweden. Among people living today, Sardinians retain the most DNA from those early farmers, whose genes suggest that they had brown eyes and dark hair.
H/T to PaleoAnthropology+ for the link.
