Humans: You Have a New Cousin

archaeological conference participants inside Denisova caveGenetic material pulled from a pinky finger bone found in a Siberian cave shows that a formerly unknown type of pre-human lived alongside modern humans and Neanderthals.

The creature, temporarily nicknamed “Woman X”, could have lived as recently as 30,000 years ago and seems only distantly related to modern humans or Neanderthals.

Johannes Krause of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said, “It really just looked like something we had never seen before… It was a sequence that looked something like humans but really quite different.”

Krause and colleagues said that they sequenced DNA from the mitochondria, a part of the cell, which is passed down virtually intact from woman to offspring. They compared it to the DNA of humans, Neanderthals and apes.

The sequence indicates the hominid’s line diverged about a million years ago from the line that gave rise to both humans and Neanderthals and that split about 500,000 years ago.

This makes it younger than Homo erectus, the pre-human that spread out of Africa to much of the world roughly 1.9 million years ago.

“It is some new creature that has not been on our radar screen so far,” said Svaante Paabo, Krause’s colleague who specializes in analyzing ancient DNA. “There were at least three …different forms of humans in this area 40,000 years ago.”

Krause and Paabo are not naming the creature as a new species just yet. They are currently working to sequence nuclear DNA – the DNA which makes up most of the genetic code. This will tell a great deal more about “Woman X”.

The genetic sequence tells scientists little about what the creature would have looked like or whether it interacted with humans living in the Altai Mountains of Siberia.

The work, performed using a DNA sequencer made by Illumina Ltd, suggests a new path is opening in the identification of ancestors of humanity. Krause and Paabo had only a small fragment of bone to work with and cannot reconstruct a skeleton in the time-honored manner of most paleontologists.

But there could possibly be more there. The cold, dry conditions of the Altai Mountains preserve the DNA well. Stone tools have also been found in the area, as well as the bones of woolly mammoths but only tantalizing fragments of human bones and teeth.

Scientists have sequenced DNA from mammoths frozen in Siberia and have sequenced DNA from Neanderthals.

Paabo and Krause said that it’s theoretically possible that the creature is related to another potential third species of human – Homo floresiensis, nicknamed “hobbit”— which lived on an island in what is now Indonesia about 17,000 years ago.

The team has attempted, though to no avail, to get DNA from the bones of “hobbits”. Most pre-human skeletons have been found in warm places such as Africa, however hot, wet conditions break down DNA.

Leave a Reply

Your email address will not be published. Required fields are marked *