A new genetic analysis of 9,000-year-old hunter-gatherer remains from the Iberian Peninsula has revealed a surprising finding: the expansion of AMY1 genes for starch digestion occurred well before the advent of farming. The study, published in PNAS, used advanced paleogenomic sequencing to track the evolution of salivary amylase in European populations. The results show that these Mesolithic tribes were already genetically adapted to a high-carbohydrate diet, likely sourced from wild roots and tubers.
This finding challenges the long-held assumption that the genetic capacity to digest starch was a consequence of the 'Neolithic Revolution.' Instead, the researchers suggest that this adaptation may have actually been a pre-adaptation that facilitated the later adoption of grain-based agriculture. The study highlights the role of environmental selection in shaping the human genome long before the transition to sedentary urban life.