Fascinating Discovery About Ancient Neanderthals
IDC Researcher: Ilan Gronau
Department: Computer Science
In the press:
Denisova Cave Entrance:
Photo Credit, Bence Viola
Denisova Neanderthal Toe Bone:
Photo Credit: Bence Viola
IDC computer scientist, along with researchers and specialists around the globe, makes fascinating discovery about ancient Neanderthals
Most people may not know the difference between Neanderthal and modern humans, or that science has shown that the Neanderthals left Africa nearly half a million years before modern humans did, and that they died out slightly after modern humans ever came into Europe and Asia. But these are pretty undisputed facts to those in the know. However, just five short years ago scientists used the genome sequence from three Neanderthal bones found in Croatia to come to the discovery that present day humans living outside of Africa share more portions of their genomes with Neanderthals than do humans living in Africa today, suggesting that our human ancestors interbred with Neanderthals as they spread out of Africa. And in the wake of that discovery 5 years ago, a group of statisticians, computer scientists, geneticists, and paleontologists have extended the information even further.
To backtrack for a moment, using DNA and genome sequences to deduce information on extinct species is a relatively new line of research. It is quite unique that the results of studies like these combine three varying disciplines: genetics, paleontology and statistics. The study in 2010 utilized this triple-threat combination, however today’s findings take the science one step further, by using farther advanced computer tools and algorithms to make sense of the DNA data in a statistically substantial way. That is where Ilan Gronau comes in. Gronau, who is a Senior Lecturer in the Efi Arazi School of Computer Science at IDC, makes up the statistical factor of the equation, along with fellow first co-author, Martin Kuhlwilm, a Ph.D. student in statistical genetics from the Max Plank Institute of Evolutionary Anthropology.
In using sophisticated statistical modeling, the researchers were able to come up with a more detailed story of the Neanderthal population, including population splits, size changes and modern human interbreeding, by analyzing the genome of a Neanderthal female sequenced from one small toe bone discovered in Siberia. The most thought-provoking and paradigm-challenging discovery that they made is that Neanderthals carry traces of modern human DNA that date back to a time after the two groups were said to have separated, but before the time when modern humans were said to have expanded into Europe and Asia. This means that the two groups may have met and interbred earlier than the research of 2010 suggested.
The research essentially makes the claim that Neanderthals who allegedly lived in Europe and Asia interbred with modern humans who are understood to have lived in Africa at that time. The most likely hypothesis that would explain this riddle is that there was a small branch of modern humans who crossed from Africa to Europe and interbred with Neanderthals earlier than what we previously suspected. As proof to this, there are actually two archeological cave sites right here in Israel, in the Carmel and in Nazareth that have modern human bone remains which date back to 100 thousand years ago, way before modern humans were said to have made their way out of Africa, which lends support to this theory. Hopefully this research is just the tip of the iceberg of modern day genome and paleontology exploration through statistical analysis, as we now have so many more questions than ever before regarding our human ancestry.