Several hunter-gatherer populations independently adopted farming in the Fertile Crescent during the Neolithic period, then went on to sow the seeds of farming far and wide, a new analysis suggests. The results contribute to the debate about whether a single source population in farming's cradle spread the culture and genes associated with the hunter-gatherer to farmer transition, or whether multiple different farmer groups, potentially with multiple, localized domestications, played a role in spreading the technology. Today, despite continued insights from ancient DNA studies, the origins of farming populations in the Fertile Crescent, where farming first began, remain elusive. Scientists have widely assumed that Neolithic populations in this region were homogeneous, but some remain uncertain of this hypothesis. Here, to provide further insights, Farnaz Broushaki and colleagues sequenced the DNA from four skeletons representing early Neolithic human remains from Iran's Zagros region, the site of some of the oldest evidence for farming to date. The researchers' genetic analyses uncovered a previously uncharacterized population - one highly distinct from ancient Neolithic Anatolians, the population often considered the likely ancestors of European farmers. This suggests these Zargos-based farmers, the genetic sequences of which bear greater resemblance to modern-day Pakistani and Afghan populations, weren't the ancestors to the first farmers in Europe. Instead, they likely split from ancient Neolithic Anatolian genomes more than 40,000 years ago, the authors say, serving as a separate source of the expansion of agriculture. The results add support to the hypothesis that rather than being the handiwork of one group of farmers, the farming culture was spread to Europe, Africa and Asia by more than one source population from farming's core zone.
Source: American Association for the Advancement of Science