Advertisement

Primate ancestors adopted grass-based diet earlier than previously thought

By looking at carbon isotope levels in the ancient teeth, researchers were able to measure the changing amount of grass-based foods included in the diets of man's primate ancestors.

By Brooks Hays
Primate ancestors adopted grass-based diet earlier than previously thought
A hominin tooth found in Afar, Ethiopia. Photo by Yohannes Haile-Selassie/Johns Hopkins University

BALTIMORE, Sept. 15 (UPI) -- The transition from the trees to the ground was key in the development of humanity's ape ancestors. It also corresponded with a shift in diet, from a tree and shrub-based diet to one based on grasses.

Now, scientists say the adoption of a ground and grass-based diet happened 400,000 years earlier than researchers previously thought.

Advertisement

Scientists at Johns Hopkins University arrived at a more accurate date for the tree-to-grass transition after a comprehensive analysis of teeth fossils belonging to human ancestors unearthed in Ethiopia. Human precursors adapted to grass-based foods around 3.8 million years ago, 400,000 years earlier than prior estimates.

"A refined sense for when the dietary changes took place among early humans, in relation to changes in our ability to be bipedal and terrestrial, will help us understand our evolutionary story," Naomi E. Levin, an assistant professor of earth and planetary sciences at Johns Hopkins, said in a press release.

RELATED Oldest-ever humanlike hand bone found in Tanzania

Levin is the lead author of a new paper on the transition, published this week in the journal Proceedings of the National Academy of Sciences.

Advertisement

The fossil analysis included teeth from 16 specimens, from three different hominin species, found in the Afar region of Ethiopia. By looking at carbon isotope levels in the ancient teeth, researchers were able to measure the changing amount of grass-based foods included in the diets of humans' primate ancestors.

Researchers say plotting a more accurate timeline of human evolution will help scientists better understand what motivated our ancestors to come down form the trees and how a terrestrial lifestyle further encouraged speciation and adaptation.

RELATED Bones of early human relative found in South African cave

"Timing is critical to understanding the context for this dietary expansion among early humans in relationship to what's happening in global climate, in vegetation communities in Africa, among other mammals, and in terms of the other evolutionary changes that are happening among early humans," Levin said. "If we know the timing of events we can start to relate them to one another."

RELATED Study: Homo genus origins not dictated by body size increase

RELATED Volunteer finds ancient hominin tooth at French dig site

Latest Headlines

Advertisement
Advertisement

Follow Us

Advertisement