A new research conducted by the researchers at Santa Fe College in Gainesville, Florida reveals the origins of human alcohol consumption. According to the study, human ancestors may have begun consuming alcohol about 10 million years ago, long before modern humans began brewing booze. Human ancestors acquired ability to break down alcohol which helped them make the most out of rotting, fermented fruit that fell onto the forest floor, the researchers said. Therefore, knowing when this ability developed could help researchers figure out when these human ancestors began moving to life on the ground, as opposed to mostly in trees, as earlier human ancestors had lived.

“A lot of aspects about the modern human condition — everything from back pain to ingesting too much salt, sugar and fat — goes back to our evolutionary history,” said lead study author Matthew Carrigan, a paleogeneticist at Santa Fe College in Gainesville, Florida. “We wanted to understand more about the modern human condition with regards to ethanol,” he said, referring to the kind of alcohol found in rotting fruit and that’s also used in liquor and fuel.

To learn more about how human ancestors evolved the ability to break down alcohol, the scientists the focused on genes that code for a group of digestive enzymes called the ADH4 family. The ADH4 enzymes are the first alcohol-metabolizing enzymes to encounter ethanol after it is imbibed.

As a part of the study the Carrigan and his team of scientists collected samples of the ADH4 genes from 28 different mammals, including 17 primates and plugged them into bacteria, which read the genes and manufactured the ADH4 enzymes. Next, they tested how well those enzymes broke down ethanol and other alcohols.

The results suggested that a single genetic mutation 10 million years ago endowed human ancestors with an enhanced ability to break down ethanol.

The scientists mentioned that this mutation occurred as human beings shifted from living on trees to a terrestrial lifestyle. The ability to consume ethanol may have helped human ancestors dine on rotting, fermenting fruit that fell on the forest floor when other food was scarce.