Artificial intelligence appears to have helped evolutionary biologists to identify an ancient human ancestor, whose identity is not yet known to modern science.
Ancient Human Hybrid
In August, researchers revealed the first discovery of an ancient human hybrid, a female who died around 90,000 years ago. Her bone was found in the Denisova Cave in the Altai Mountains of Russia.
Genetic analysis revealed the ancient individuals' parents belonged to distinct human groups. She likely had a Neanderthal mother and a Denisovan father.
"The father, whose genome bears traces of Neanderthal ancestry, came from a population related to a later Denisovan found in the cave," Viviane Slon, from Max Planck Institute for Evolutionary Anthropology, and colleagues reported in Nature. "The mother came from a population more closely related to Neanderthals who lived later in Europe."
Neanderthals And Denisovans
The Neanderthals and Denisovans are two different subspecies of archaic humans. The Neanderthals settled in Europe and some parts of western Asia. The Denisovans likely settled in central Asia and Siberia, where the first bone of the species was discovered in 2008.
The two groups are genetically distinct from each other but both likely cross-bred with modern humans. Studies suggest this interbreeding gave modern humans defenses from viruses and disease. Some of the inherited genes may even have influenced the shape of the human skull and brain.
Scientists also generally think the Neanderthals and Denisovans would have mated, albeit researchers have only found one physical evidence that could prove this interbreeding.
Findings of a new study published in Nature Communications suggest the hybrid of the Neanderthal and Denisovan found in Russia was not an isolated case, but part of a more general introgression process.
AI Predicts Unknown Human Ancestor
Òscar Lao, from the Centro Nacional de Análisis Genómico (CNAG-CRG) at the University of Tartu and colleagues used deep learning algorithms and statistical methods to study human evolution.
The researchers trained an algorithm so it can predict human demographics using genomes obtained from hundreds of thousands of other simulations.
"Deep learning allows us to observe what makes the ancestral puzzle fit together," Lao explained.
Their research identified in the genome of a human ancestor, the footprint of a new hominid, which would have been a hybrid of the Neanderthals and the Denisovans. Results of DNA computational analysis also show the extinct species cross bred with Out of Africa modern humans in Asia.
"In addition to the reported Neanderthal and Denisovan introgressions, our results support a third introgression in all Asian and Oceanian populations from an archaic population," the researchers wrote.