An analysis of the blood types of a Denisovan and three Neanderthals has revealed new clues about evolutionary history, the health and vulnerabilities of their populations.
Among other conclusions, its African origin is confirmed, as well as the weakness of its fertility and its susceptibility to viral infections, leading to a high infant mortality rate.
Neanderthals and Denisovans were ancient humans who lived throughout Eurasia, from Western Europe to Siberia, between 300,000 and 40,000 years ago. In previous research, DNA sequences from the complete genome of 15 of these ancient individuals were obtained, which has allowed us to better understand their species. However, despite being encoded in DNA, the blood types of these ancient individuals have received little attention.
In the new study, published in the magazine ‘PLOS ONE’, Center National de la Research Scientifique (CNRS) researcher Silvana Condemi and her colleagues from the University of Aix-Marseille (France) investigated the previously sequenced genomes of a Denisovan and three Neanderthals (from 100,000 to 40,000 years ago) to determine their types blood test and analyze the implications. Although there are 43 different systems for assigning blood types, The researchers focused on seven systems that are often used in the medical field for blood transfusions..
This analysis of the blood types of the four individuals revealed new information about their species. For example, ancient individuals had blood type alleles – different versions of the same gene – in combinations that are consistent with the idea that Neanderthals and Denisovans originated in Africa.
Furthermore, a clear genetic link between Neanderthal blood types and the blood types of an Australian Aboriginal and an indigenous Papuan suggests the possibility of a mating between Neanderthals and modern humans before modern humans migrated to Southeast Asia.
Neanderthal individuals also had blood type alleles associated with increased vulnerability to diseases that affect fetuses and newborns, as well as lower variability of many alleles compared to modern humans. This pattern is in line with existing evidence linking low genetic diversity. and poor reproductive success with the eventual disappearance of Neanderthals.
Overall, these results highlight the importance of blood types in understanding the evolutionary history of humans.
The authors emphasize that “this work identifies the blood group systems in Neanderthals and Denisovans to better understand their evolutionary history and consolidate the hypotheses regarding their dispersal in Eurasia and interbreeding with the first ‘Homo sapiens'”.