An international team of researchers has discovered 13 fossil teeth in Ethiopia's Afar region that do not fit any known human species. The find suggests that multiple hominid lineages coexisted in Africa more than two million years ago, including one that science had not yet identified.

Human brains have been shrinking since prehistoric times, some studies suggest. Whether this is true and why it has happened are debated.

Dr. Brian Villmoare of the University of Nevada – Las Vegas shares how his team found teeth in Ethiopia and what those teeth might mean in terms of who was around when in the evolutionary record.

A study on Ozempic’s impacts on Alzheimer’s disease didn’t have the results scientists hoped for. We talk to UNLV’s Dr. Jeffrey Cummings on the research and what’s next. Also from UNLV: a look at how a “new” species of an ancient human ancestor can help shape our view on evolution. We end with a fun story on “Silver Belle”... the first tree from Nevada to serve as the U.S. Capitol Christmas Tree!

In mid-August, the science journal Nature published UNLV research about a newly discovered species of human ancestors. A group of scientists traveled to Ethiopia, where they found 13 teeth fossils. Some of them belonged to the genus Homo — yes, the same genus modern humans belong to. But they also found a set of teeth that belonged to a new species of the genus Australopithecus, indicating that both species were present in Africa at the same time a little over 2 million years ago. 

The appearance of the genus Homo is close to the Plio-Pleistocene boundary, reflected by fossils reported recently by Brian Villmoare and his colleagues and well dated at about 2.8 million years ago. The origin of Homo may relate to changes in temperature and associated changes in habitat, as recognised five decades ago by South African palaeontologists Elisabeth Vrba and Bob Brain, although they emphasised a date of 2.5 million years ago.

Researchers have discovered a new species of human ancestor that existed alongside Homo sapiens.

We were never alone, until recently at least. Just as there are multiple giraffe species in Africa, there were multiple human species, and some overlapped in time and space.