Report: Farming did not erase genetic diversity


New genetic analysis of people living in Papua New Guinea shows a sharp genetic divide between 10,000 and 20,000 years ago that was likely determined by whether their ancestors lived a more nomadic life in the highlands or a more sedentary one in the lowlands.
Abstract New Guinea shows human occupation since 50 thousand years ago (ka), independent adoption of plant cultivation 10 ka, and great cultural and linguistic diversity today.
Study author geneticist, Chris Tyler-Smith and his colleagues, performed genome-wide single-nucleotide polymorphism genotyping on 381 individuals from 85 language groups in Papua New Guinea.
They found a sharp divide originating 10 to 20ka between lowland and highland groups and a lack of non–New Guinean admixture in the latter.
All highlanders share ancestry within the last 10 thousand years, with major population growth in the same period, suggesting population structure was reshaped following the Neolithic lifestyle transition.
However, genetic differentiation between groups in Papua New Guinea is much stronger than in comparable regions in Eurasia, demonstrating that such a transition does not necessarily limit the genetic and linguistic diversity of human societies.
Why it matters:
The genetic divide began at about the same time people began farming in the lowlands.
In other parts of the world during the Bronze and Iron Ages, migration and innovations were the prime forces that shaped human evolution.
But that doesn’t seem to be the case in Papua New Guinea, where the transition to cultivating crops had the opposite effect. Tyler-Smith told
Science that “is a big surprise.”
How they did it:
Researchers analyzed the genetic makeup of 381 people from 85 different language groups across Papua New Guinea, and also analyzed 39 genome sequences that had been previously generated from people there.
What it means:
The researchers say the findings may indicate technological advances in the Bronze Age — not earlier agricultural ones — may have wiped out genetic groups in Europe, per Science.