Deep in the DNA of Asians hidden genetic hint indicating the existence of unknown human ancestor. Remarkably, this striking hypothesis came not a man but an artificial intelligence algorithm. Welcome to the archaeology of the 21st century. A new study published last week in Nature Communications, suggests that not yet discovered hominids interbred with modern humans tens of thousands of years ago.
Lost human ancestor?
This mysterious species eventually became extinct, but the AI developed by scientists from the Institute of evolutionary biology and several other European institutions, found traces of its existence in the DNA of modern humans of Asian descent. In a press release issued by the Center for genome regulation, it is stated that for the first time to explain the history of mankind has used deep learning that “paves the way for the application of this technology in other questions in biology, genomics and evolution”.
According to a new study of the mysterious hominid, probably is a hybrid of Neanderthals and Denisovsky people. The Neanderthals who lived in Europe, and denisovans, which has spread to Siberia, South-East Asia and Oceania, was closely associated group of early humans separated from a common ancestor in the order of 744 000 years ago. When anatomically modern humans (Homo sapiens) evolved in Eurasia from Africa, they mingled and interbred with Neanderthals and denisovans, which we know from genetic research. In addition to a large amount of DNA left by Neanderthals, Denisovsky researchers extracted DNA from well-preserved finger bone found in a Siberian cave. Today we find traces of these extinct species into the DNA of non-African people, even though Asians only retained the genetic heritage of the Denisovsky people.
However, the latest study shows that modern people, in addition to interbreeding with Neanderthals and denisovans, interbred with the third as yet unknown species.
This idea is not new. In 2016, a genetic study co-Mauja Mandala of the University of Tartu and Jaume of Bertranpetit from the University Pompeu-Fabra has provided evidence that the indigenous Australian population from South and South-East Asia “holds a small fraction of the ancestry of an unknown extinct hominid, and this lineage is absent in Europeans and vostochnaia”. Their new research dedicated to finding, where did this small percentage.
To this end, Mondal and Bertranpetit presented evidence in the form of demographic analysis, which was based on deep learning and complemented by statistical analysis. Their algorithm was developed and compared many complex demographic model to make predictions about the story events of incest in Eurasia. For this, the researchers fed the algorithm a meal of genome sequence, obtained both from modern and ancient DNA, which allowed the neural network to generate a large set of possible demographic histories. Statistical analysis further calculated which of these stories was most likely.
The team used deep learning to teach the algorithm to “predict human demographics” in the process hundreds of thousands of simulations, says Oscar Lao, the principal investigator of the Centre national science and genetics. “Whenever we conduct the simulation, we travel in the possible path in the history of mankind. Using these simulations, deep learning allows us to observe the origin of this puzzle with a pedigree”.
The gathering together of this genetic mosaic led to the alleged “third archaic introgression” refers to the third event of hybridization among ancient people (the other two genetic mixture between modern humans and Neanderthals and modern humans and Denisovskoe). Modern humans interbred with an unknown third, models indicate that it is either Neanderthal-Denisovskaya hybrid, or an early offshoot of the lineage Denisovskaya.
The fact that the Neanderthals and denisovans, with common ancestry, can interbreed, no surprise. Last year, scientists found a 90,000-year-old remains of one such hybrid human — girl with her mother Neanderthal and dad Denisovsky person. Due to lack of evidence, scientists were not sure that it was happening on a regular basis. A new study supports the assumption that two extinct species breed often enough to produce genetically distinguishable hybrid population.
Serena Tucci, an ecologist and evolutionary biologist at Princeton University, in the past year have used genetic evidence to show that early modern humans mated with Denisovskaya populations at least twice. This means that lingering traces Denisovskaya DNA contained in the genome of Asians living today, comes from at least two separate populations of Denisov.
As to the allegations of the existence of some unknown human species, Tucci says that to assume outside the available evidence is not necessary.
Without a doubt, need more proof. However, the latest research should encourage archaeologists to look for additional clues on the existence of intended.
As you can see, the use of AI in archeogenetics — very cool. What do you think, where else can I apply these ideas? Tell us about it in our chat in Telegram.