With one of America’s biggest drinking holidays approaching on New Years Eve, new research shows humans may have developed the ability to process alcohol nearly 10 million years ago.
According to a study published earlier this month, our human ancestors acquired the ability while eating rotten fruit. They lived in trees and ate the fallen, fermented fruit as they transitioned to living on the ground.
Matthew Carrigan, a biology professor at Santa Fe College, led the research team that conducted the seven-year study at the Foundation for Applied Molecular Evolution, and the research was published in “Proceedings of the National Academy of Science.”
The team found a gene mutation among ancestral gorillas and humans during the same time period Earth underwent a cooling phase and humans transitioned from forests to grasslands — a connection that led them to the discovery, Carrigan said.
“When we looked at this mutation and we tried to interpret whether this mutation was actually a beneficial adaptation to the organism at that time, we started to look at what else was going on at that time from other studies,” he said.
The ethanol-active enzyme researchers located was Alcohol Dehydrogenase 4.
“We suspect that most organisms living before this mutation would have avoided fermented fruit because it would’ve led to intoxication,” he said.
Although evidence shows human ancestors adapted to ethanol 10 million years ago, he said, it’s not a perfect adaptation in today’s world.
“Our environment has changed so much,” Carrigan said. “Rather than having a low concentration of ethanol found rarely in fruit, we now have much more highly concentrated ethanol available at almost every corner convenience store.”
Carrigan said this abundance of ethanol has led to several new diseases for humans over the years, including alcoholism.
“This new understanding may lead to improved ways to treat or prevent alcohol-related diseases,” Carrigan said. The study was funded by the National Institute on Alcohol Abuse and Alcoholism.
David Houder, Santa Fe College spokesman, said Carrigan’s study has garnered international exposure for the college.
“It’s validating for us,” Houder said. “We know the good work that all of our professors are doing already, and I think it just speaks to the high quality of education one can receive at Santa Fe College.”
[A version of this story ran on page 9 on 12/7/2014]