La Trobe University molecular archaeologists Cristina Valdiosera and Colin Smith, in collaboration with colleagues from Uppsala University in Sweden and several universities across Spain, analysed the remains of 13 people aged 7,250 to 3,500 years old, from the north and south of Spain.

Their findings have been published in the prestigious journal Proceedings of the National Academy of Sciences (PNAS).

Dr Valdiosera said genetic analysis had allowed the research group to understand the impact of 4000 years of human migration in Iberia (modern day Spain and Portugal), spanning the Neolithic Age to the Bronze Age.*

“We found early Neolithic migration into the Iberian Peninsula established a distinct and continuous population that was more persistent and less affected by late Neolithic migrations, than in populations elsewhere in Europe,” Dr Valdiosera said.

The study demonstrated that Neolithic Iberians showed genetic differences to the migrant farmers who settled in central and northern Europe.

“This suggests that all early farmers in Iberia trace most of their ancestry to the first Neolithic people that migrated into the peninsula and that later contributions from their central European counterparts were only minor,” Dr Valdiosera said.

“Following a period of relatively low genetic diversity in early Neolithic Iberia, diversity increased as the population grew and the migrant farmers mixed with local hunter-gatherers.”

The study also looked at the diet of Neolithic farmers over 4000 years and found that despite the significant biological interaction between culturally different groups, the farming culture was dominant.

Colin Smith said while they did see a substantial genetic influx of hunter-gatherer ancestry into farmers over time, their diets did not change.

“Their terrestrial diet is characteristic of farming cultures and persist temporally and geographically across the millennia,” he said.

Dr Valdiosera said the study illustrated the power of interdisciplinary research to understand the full complexity of European prehistory.

“Overall, these results emphasise the differences between the westernmost populations and their central European counterparts and highlight the need for detailed regional studies to reveal the full complexity of prehistoric migrations,” she said.