The waves of new arrivals that populated Neolithic Europe left genetic legacies among their descendants, through which we can learn a lot about how they occurred. The two most important Neolithic migrations offer a sharp contrast, with one involving mostly men, while the other was made up of men and women in equal numbers.
It is believed that 8,000-9,000 years ago people migrated out of Anatolia, now the Asian part of Turkey, and into Europe, bringing with them the great technology of the day, agriculture. Historians first theorized this event based on studies of European languages and archeology, and genetic research has provided supporting evidence.
Professor Mattias Jakobsson of Uppsala University has explored the sex chromosomes these Anatolian farmers brought with them. Based on the genetics of 36 people buried in Europe during the Neolithic era (12,000-4,000 years ago), Jakobsson concludes in Proceedings of the National Academy of Sciences that the migration involved almost as many women as men. Although it is impossible to prove, it seems likely the migration involved whole families, contradicting theories that early agricultural families tended to stay close to the lands of male partner's parents.
On the other hand, during the late Neolithic/early Bronze Age another population arrived in Europe from the area north of the Black and Caspian Seas, and this time their genetic legacy was very different. The sex chromosomes they passed on to subsequent generations indicate that the migration was almost entirely men. “There are simply too few X-chromosomes from the migrants, which points to around 10 migrating males for every migrating female," Jakobsson said in a statement.
Jakobsson and his co-authors conclude the latter migration represented one of conquest. Where the Anatolians benefited from superior food production, possibly leading to a population boom that caused people to gradually spread out, the arrivals from the Caspian region were probably making use of military advances. Since it is believed this is the region, and approximately the time, where horses were first domesticated, Jakobsson's findings are not hard to explain.
Rather than a single terrifying wave of conquest, Jakobsson's data suggests several generations of men arrived from the east. In the absence of written records we know little about what occurred, and the genetics cannot tell the difference between those who set themselves up as overlords of the places they conquered, and those who made raiding missions for plunder. Either way, however, it is unlikely this was a good time to have been a member of the pre-existing European population.
Although there have been many other migrations into Europe, these two are considered to have made the most impact since the end of the last Ice Age. Both are thought to have had enormous, and enormously different, cultural legacies.
