Fossil Teeth Study Claims No Hominin is the Common Ancestor of Neanderthals and Modern Humans

Ever since the first Neanderthal fossil was discovered, its relationship with hominins and modern humans has been a subject of much debate. A latest study based on fossil teeth analysis claims that there is no known hominin that is a common ancestor of Neanderthals and modern humans.

Neanderthals were the closest living relatives of modern humans who lived across vast regions that ranged from Europe to Middle East to Western Asia. And studies that compared the mtDNA of Neanderthal and Homo Sapiens suggest that they diverged from a common ancestor some 350,000-400,000 years ago. Since then researchers have been on a constant hunt for the common ancestor that linked modern humans with Neanderthals. But the new study states that the relationship of the homo sapiens with the Neanderthals will remain a mystery.

According to the latest study conducted by team of scholars from The George Washington University, Konrad Lorenz Institute for Evolution and Cognition Research in Austria, Indiana University and Atapuerca Research Team in Spain, no known hominin is the ancestor of Neanderthals and modern humans. They concluded this after analyzing  dental fossil samples.

With the help of qualitative methodology the team examined the shape of dental fossils, approximately 1,200 molars and premolars. They looked at the pattern of points in molars of European fossils, older African fossils, Asian fossils and modern humans. They reconstructed the dental morphology of the last common ancestor. They noticed that none of the fossil records matched with the ancestor morphology that they calculated as the ancestor.

"None of the species that have been previously suggested as the last common ancestor of Neanderthals and modern humans has a dental morphology that is fully compatible with the expected morphology of this ancestor," Aida Gomez-Robles, an anthropologist at George Washington University and lead author, said in a statement.

Gomez-Robles was quoted in LA Time saying, "We think that we didn't find it because we actually don't have this ancestor in the fossil record."

A study published last week that looked at the 1.8 million-year-old skull claimed that all homo species were one. This finding shattered the concept which claims all members of homo genus that include Homo habilis, Homo rudolfensis, Homo erectus are in fact different. The skull dubbed Skull5 indicated that all the early homo species had small brains.

Several fossils were offered as a candidate for the common ancestor to Europeans. One such fossil was the Homo heidelbergensis- the tall and strong species that roamed out of Africa less than 800,000 years, reports LA Times.

The study also discovered that the potential human ancestors that were discovered in Europe are morphologically closer to Neanderthals than modern humans. Neanderthals rose  1 million years ago and the humans deviated much earlier than 350,000 years ago as believed earlier.

The researchers conclude saying, "Our primary aim is to put questions about human evolution into a testable, quantitative framework and to offer an objective means to sort out apparently unsolvable debates about hominin phylogeny."

They believe that only studying the hominin fossils of Africa can they answer questions regarding human ancestors.

The article, "No known hominin species matches the expected dental morphology of the last common ancestor of Neanderthals and modern humans," is published in the Proceedings of the National Academy of Sciences.