"Europe's prehistory was shaped by the advancement and retreat of ice sheets during the Last Ice Age, which reached its peak 18,000 years ago. Humans had entered Europe about 20,000 years earlier, but the advancing ice sheets meant that only the southern fringes of Europe were inhabitable. Places like the Iberian and Italian Peninsulas, as well as parts of the Balkans, served as refugia, where humans survived for thousands of years, weathering the storm. But when the ice began to retreat about 15,000 years ago, the ancestors of many present-day northern Europeans moved northward. A few thousand years later, humans from the Near East began to expand into Europe as well, some of them bringing new languages and new lifestyles, including agriculture.
We consider Europe to be bounded to the west and north by the Atlantic Ocean, to the south by the Mediterranean Sea, and to the east by the Caucasus Mountains of western Russia. Our database reflects some of the genetic diversity of northern Europe prior to the era of intercontinental travel that began roughly 500 years ago." - 23andme
