New research indicates that early duplications of the salivary amylase gene (AMY1) may have started more than 800,000 years ago, long before humans began to farm. These duplications opened the door for the wide genetic variations that still exist today and help us digest starchy foods. The findings are detailed in a study published October 17 in the advanced online issue of the journal Science. The team also found that AMY1 gene duplications occurred in both Neanderthals and Denisovans.

Scientists in their latest research highlight origin and reason for humans' love for a starchy diet

The latest study reveals that the salivary amylase gene may have duplicated as early as 800,000 years ago, long before the advent of farming, and may have contributed to the evolution of human adaptation to starchy foods.

The findings are detailed in a study published on Thursday in the advanced online issue of the journal Science, which shows that the AMY1 gene is much older than previously thought.

“This suggests that the AMY1 gene may have first duplicated more than 800,000 years ago, well before humans split from Neanderthals and much further back than previously thought,” Kwondo Kim, a study co-author and computational biologist at The Jackson Laboratory for Genomic Medicine in Connecticut, was quoted by the journal as saying.

The study also examines how agricultural development affected AMY1 variation. Early hunter-gatherers had multiple gene copies, but early European farmers saw an increase in the average number of AMY1 copies over the last 4,000 years. This could be attributed to their starch-rich diets after adopting farming.

“The idea is that the more amylase genes you have, the more amylase you can produce and the more starch you can digest effectively,” the study co-author and University of Buffalo evolutionary anthropologist Omer Gokcumen said.

Explaining the consequences of the findings and the future of the research, study co-author Jackson Laboratory computational scientist Feyza Yilmaz said: “Given the key role of AMY1 copy number variation in human evolution, this genetic variation presents an exciting opportunity to explore its impact on metabolic health and uncover the mechanisms involved in starch digestion and glucose metabolism.​​

“Future research could reveal its precise effects and timing selection, providing critical insights into genetics, nutrition, and health.”