Neanderthal, Denisovan Blood Group Analyses: Study Confirms Hypotheses on Their Origin, Dispersal, and Interbreeding with Homo Sapiens

A team of researchers from the Anthropologie Bio-Culturelle, Droit, Éthique et Santé research unit recently showed analyses for three Neanderthals and a Denisovan.

According to a EurekAlert! report, the team verified hypotheses concerning the groups' African origin, their Eurasian dispersal, and interbreeding with early Homo Sapiens.

Additionally, the researchers discovered more evidence of low inherent diversity and possible demographic fragility. The Neanderthals and Denisovans' non-existent hominin lineages existed all over Eurasia from up to 300,000 years ago.

Nonetheless, blood group systems were the original markers anthropologists used in order to restructure the hominin populations' origins, including how they migrated and interbred.

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Previously Sequenced Genomes Studied

In a new study, researchers from the CNRS, Aix-Marseille University, and the French Blood Establishment, have investigated previously sequenced genomes of a Denisovan individual and three Neanderthal females who lived between 100,000 and 40,000 years ago in order to determine their blood groups and deliberate what they possibly reveal about human evolution.

Out of roughly 40 identified blood group systems, the study team focused on seven blood group systems that are commonly regarded for the purpose of blood transfusion, the most common of which are identifying blood types A, B, AB, and O or ABO, and Rh systems.

The findings support previous ideas while also revealing new ones. While it has long been assumed that Neanderthals had type O blood, like chimps, who all have type A, and gorillas, who all have type B, the researchers discovered that these ancient hominins already had the complete ABO variable range observed in contemporary humans.

Both Neanderthals and Denisovans have genes that point to African origins, according to a broad study that includes various blood type systems.

According to a similar HeritageDaily report, the discovery that Neanderthals had a unique RH gene not seen in contemporary humans, with the notable exceptions of a single Aboriginal Australian and a Papuan, is particularly unexpected.

Neanderthals' Interbreeding

In relation to Neanderthal's Interbreeding, a report from Smithsonian Institute specified that although a modern human who lived about 40,000 years ago was discovered to contain between 6-9% Neanderthal DNA, Neanderthals only contributed around 1-4% of the genomes of non-African modern humans.

The evidence of modern human-Neanderthal interbreeding gives insight into the modern human spread out of Africa.

Furthermore, these new findings counter a lot of past hypotheses in which anatomically, modern humans replaced archaic hominins, such as Neanderthals, sans any interbreeding.

Nevertheless, even with some interbreeding between today's humans and the now-inexistent hominins, most of the genome still originates from Africa.

Neanderthals could not have contributed to the genomes of contemporary Africans since they evolved and lived only in Eurasia and so could not have mated with the humans who were in Africa at the time.

Vulnerability to 'Hemolytic Diseases' of the Fetus and Newborn

The study "Blood Groups of Neandertals and Denisova Decrypted," published in PLoS One, sheds light on Neandertal demographics, according to Heritage Daily.

Specifically, it verifies that these ancient hominins showed very small genetic diversity. The study also confirms that these ancient hominins may have been susceptible to haemolytic disease of the fetus and newborn (erythroblastosis fetalis) in cases where Neandertal mothers were carrying the children of Homo sapiens or Denisovan mates due to maternofetal Rh incompatibility.

These findings support the theory that the extinction of Neandertals was caused by a lack of genetic variety combined with poor reproductive performance.

Related information about Neanderthals is shown on KPIX CBS SF Bay Area's YouTube video below: