A new study published in Science has challenged the prevailing assumption that early humans were predominantly meat-eaters. Recent archaeological findings and genetic analyses reveal that carbohydrates played a more significant role in prehistoric diets than previously thought. The research indicates that early humans had already developed the ability to digest starch-rich foods long before the advent of agriculture.
The key to this adaptation lies in the AMY1 gene, responsible for producing the enzyme amylase, which converts complex carbohydrates into simple sugars. Researchers discovered that this gene was actively replicating in ancient human populations, suggesting that the preference for carbohydrates emerged as a natural evolutionary response rather than a product of agricultural development. Genomic analysis of 68 ancient individuals, including a 45,000-year-old Siberian sample, revealed multiple copies of the AMY1 gene even in pre-agricultural hunter-gatherer societies.
The findings, as highlighted by study co-author Omer Gokcumen, show that humans with more AMY1 gene copies were likely better at digesting starch, providing a survival advantage that increased their reproductive success over time. This adaptation is not unique to Homo sapiens; evidence shows that Neanderthals and Denisovans also carried multiple copies of the AMY1 gene, suggesting the duplication began over 800,000 years ago, well before humans diverged from these ancestral species.
Interestingly, the study noted that the average number of AMY1 copies surged further with the rise of agriculture, as diets became increasingly dependent on starchy foods such as grains. However, the number of AMY1 copies varies among modern populations, reflecting differences in historical dietary patterns.
These insights shed light on how early humans adapted to diverse environments by modifying their diets to meet nutritional needs, underscoring the importance of genetic variation in the evolution of human health and metabolism.
These findings reshape our understanding of human evolution, showing that the ability to consume and process carbohydrates was a vital survival strategy long before the rise of agriculture. The AMY1 gene’s duplication reflects an evolutionary response to environmental challenges, providing early humans with a metabolic edge in starch-rich habitats. As farming practices evolved, the dependence on carbohydrates grew, reinforcing this genetic adaptation. However, variations in AMY1 gene copies among modern populations suggest that dietary patterns have continued to evolve based on cultural and environmental influences. These insights highlight the complex interplay between genetics, environment, and diet in shaping human health over millennia, emphasizing the significance of genetic diversity in metabolic resilience and adaptation. The study’s revelations offer a new lens through which to examine the relationship between nutrition, genetics, and evolution—reminding us that our dietary preferences are deeply rooted in ancient survival strategies.
Reference:
1. Reconstruction of the human amylase locus reveals ancient duplications seeding modern-day variation. Accessed October 26, 2024. https://www.science.org/doi/10.1126/science.adn0609.
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