Study Finds Agriculture Accelerated Human Genome Evolution to Capture Energy from Starchy Foods

A study led by Peter Sudmant of the University of California, Berkeley, and Erik Garrison of the University of Tennessee Health Science Center in Memphis found that the increase in the number of genes coding for enzymes that break down starch tracks the spread of agriculture across Europe from the Middle East, and with it, an increasingly starchy human diet rich in high-carbohydrate staples such as wheat and other grains.

The study, published in the journal Nature, also provides a new method for identifying the causes of diseases that involve genes with multiple copies in the human genome, such as the genes for amylase. The researchers discovered that, around 12,000 years ago, humans across Europe had about four copies of the salivary amylase gene. That number has now increased to about seven. The combined number of copies of the two pancreatic amylase genes also increased by half a gene (0.5) on average over this time in Europe.

The researchers also found that amylase genes also increased in other agricultural populations around the world and that the region of the chromosomes where these amylase genes are located looks similar in all these populations, no matter what specific starchy plant that culture domesticated. These findings reveal that as agriculture arose independently around the world, it seems to have rapidly altered the human genome in nearly identical ways in different populations to deal with increased carbohydrates in the diet.

For more details about this study, read the article in UC Berkeley News.