Who doesn’t love a spud? From bangers and mash to fish and chips, potatoes have been a staple in many cultures diets. The humble potato became an agricultural crop thousands of years ago and originated from Peru before spreading around the world. Using DNA analysis researchers from Emory University have shown that ancient populations of the Peruvian highlands adapted to the introduction of agriculture and an extreme, high-altitude environment in ways distinct from other global populations.
“We see a different configuration of a gene associated with starch digestion in the small intestine—MGAM—in the agricultural ancient Andean genome samples, but not in hunter-gatherers down the coast,” says the first author of the paper John Lindo, a geneticist at Emory University. “It suggests a sort of co-evolution between an agricultural crop and human beings.”
In contrast, European populations that began consuming more grains with the rise of agriculture show different genomic changes. Research has shown that their genomes have an increased number of copies of the gene coding for amylase—an enzyme in saliva that breaks down starch.
The researchers used DNA samples dating back as far as 7,000 years and compared them to modern-day genomes from both the highland Andean populations and lowland populations in Chile, to identify genetic adaptions that took place before the arrival of Europeans in the 1500s.
The location for this study is fairly unique due to the strong selective pressures required for ancient populations to thrive at heights greater than 2500 metres, “Frigid temperatures, low oxygen levels, and intense ultraviolet radiation make the highlands one of the most extreme environments that human beings have occupied,” Lindo says. “It provides a glimpse of our potential for adaptability.”
The research fits with archaeological evidence that indicates that the potato was domesticated around 3400 years ago and that both ancient and modern high-altitude populations showed strong positive selection on variants in the MGAM gene.
“Understanding the diet, environment, and historical events of various ancestries, and how those ancestries adapted to these factors, may be one way to understand some health disparities among different populations,” Lindo says.
The findings appear in the journal Science Advances.
Researchers from the University of Chicago; the University of California, Merced; and the University of California, Davis also contributed to this work.
Source: Emory University
