Agriculture spread into the Mediterranean from the Near East at the end of the Late Glacial period 13,000 years ago, thousands of years earlier than we previously thought, a study has revealed. This new hypothesis indicates that farmers then colonised other parts of Europe, bringing with them their agricultural practices.
Scientists have long attempted to characterise how farming spread into Europe, but many uncertainties remain, especially since studies of contemporary genetic variation and ancient DNA have sometimes yielded contradictory results.
A popular theory is that farming originated from the Near-East and first spread to Mediterranean countries and to the rest of Europe during the Neolithic era, around 8,000 years ago.
Early European farmers indeed seem to share genes with people from that the Near East. However, clear ancient DNA evidence from Mediterranean Europe is lacking to confirm this timeline.
Arrival of the farmers
In the study now published in the Proceedings of the Royal Society B, the scientists from the University of Huddersfield used almost 1,500 mitochondrial genome lineages to date the arrival of farmers in different regions of Europe.
There is an acute shortage of pre-Neolithic skeletal remains from which ancient samples can be taken in Mediterranean countries. Compared to previous studies, they were able to obtain this amount of genetic material by looking at modern DNA samples.
"We haven't been able to fill the gap with ancient DNA, so we found a way to get round that by looking at modern samples. Instead of dating the lineages across Europe as a whole we have dated them firstly in the Mediterranean area and then we have looked at what happens if you assume that they have arrived in that area and then moved on," lead author Martin Richards said.
The analyses confirmed that farming came from the Near East and reached the Mediterranean before taking roots in the rest of Europe.
But the scientists were surprised to discover that the first people to arrive in the central and eastern Mediterranean reached the region during the Late Glacial period, 13,000 years ago. This is much earlier than previously thought.
These people then moved to the rest of Europe thousands of years later, taking with them all the farming practices they had acquired, as well as an important genetic heritage from the Near-East.
"This supports a scenario in which the genetic pool of Mediterranean Europe was partly a result of Late Glacial expansions from a Near Eastern refuge, and that this formed an important source pool for subsequent Neolithic expansions into the rest of Europe", the authors write.