Researchers working in Ethiopia’s Afar region have discovered a new species of human ancestor, according to a study recently published in the journal Nature.
The endeavor was led by the illustrious Ledi-Geraru Research Project, which previously discovered the earliest-known Homo sapien specimen as well as the oldest cache of stone tools. The new study found that two completely different species of human ancestors cohabitated somewhere between 2.6 and 2.8 million years ago. The team of international researchers, headed by Arizona State University, found 13 fossilized teeth which they determined belonged to “a previously unknown” species of Australopithecus which existed side-by-side with the earliest Homo sapiens.
Discovery Challenges What’s Known About Evolution
This discovery challenges the notion that evolution was less a linear development and more of a “bushy tree,” in the words of researchers. “Here we have two hominin species that are together. And human evolution is not linear—it’s a bushy tree; there are life forms that go extinct.”
“This new research shows that the image many of us have in our minds of an ape to a Neanderthal to a modern human is not correct—evolution doesn’t work like that,” explained Kaye Reed, a research scientist at Arizona State University’s Institute of Human Origins and the project’s co-director.
Further Research Will Focus on Teeth
Further research will focus on the isotopic analysis of tooth enamel, which will determine the species’ dietary patterns and social practices. Isotopic analysis utilizes chemical signatures preserved within the teeth to reconstruct what these people ate and how their bodies adapted to their changing environment.
“The new finds of Homo teeth from 2.6-to-2.8-million-year-old sediments confirms the antiquity of our lineage,” added lead author Brian Villmoare. “We know what the teeth and mandible of the earliest Homo look like, but that’s it. This emphasizes the critical importance of finding additional fossils to understand the differences between Australopithecus and Homo, and potentially how they were able to overlap in the fossil record at the same location.”
