Prehistoric cannibal tooth is a grisly revelation of the oldest human DNA ever

Humans have a past, both in the sense of evolution and of certain behaviors we’d rather forget... like cannibalism.

Homo antecessor was the ancestor of Homo sapiens that butchered and feasted on its own kind. When the cannibalized bones of this hominid were first unearthed in 1994, no one had any idea they contained the oldest human DNA in existence. Now, a team of scientists from CENIEH (National Research Center on Human Evolution) in Burgos, Spain and the University of Copenhagen have discovered genetic data in an 800,000-year-old tooth — genes that reveal how this species was related to us.

“Ancient protein analysis provides evidence for a close relationship between Homo antecessor, us (Homo sapiens), Neanderthals, and Denisovans. Our results support the idea that Homo antecessor was a sister group to the group containing Homo sapiens, Neanderthals, and Denisovans”, said Frido Welker, a University of Copenhagen postdoc who recently published a study in Nature.

Just one thing before you start writing your next horror movie script: the DNA-loaded proteins found in the tooth did not belong to another Homo antecessor who had previously been eaten, but to the same unfortunate soul who was consumed.

What that tooth can tell us is much more than the fact that it once ate its own kind. Which hominid was the predecessor of all humans is unclear, and because DNA chemically degrades over time, the oldest specimen of human DNA anyone had found before was only around 400,000 years old. Anything else we know about ancient hominids was inferred from fossils. Using an approach known as paleoproteomics, the team analyzed the DNA in proteins from the Homo antecessor tooth with mass spectrometry to see what they could find out.

"We look forward to sequencing more ancient hominin proteomes to further resolve existing questions in human evolution," Welker told SYFY WIRE about his team's future ambitions for paleoproteomics, which was developed at the University of Copenhagen.

When Homo antecessor was first discovered, it was assumed this species was the ancestor of both Neanderthals and Homo sapiens. Supporting research suggests that while they all had some physical characteristics in common, it was later determined that Homo antecessor’s facial features were much closer to those of modern humans than Neanderthals and other more recent subspecies.

"H. antecessor is likely to be as closely related to Homo sapiens as it is to Neanderthals or Denisovans," Welker said. "However, previous research has shown that some facial features, particularly those related to the bone structure below our cheeks is rather similarly shaped in H. antecessor and H. sapiens. As a result, some aspects of our facial features might have very deep evolutionary ancestry, while the differently-shaped cheeks of Neanderthals are a derived trait that evolved during Neanderthal evolution."

Why did paleo-humans cannibalize each other anyway? While there have been hypotheses about territorialism, that still remains an unsolved mystery.

(via University of Copenhagen)