A group of scientists has discovered that a rare blood disorder could have had a severely negative impact on the offsprings of Neanderthals, as a result of sexual relations between human beings and Neanderthals. The study was published in PLOS one journal. The current finding is that Neanderthals had the same blood groups, A, B, and O just like modern humans.
According to a study, the blood samples of Neanderthals show that their blood carried a specific set of genetic variants, which was susceptible to hemolytic disease of the fetus and newborn (HDFN). Researchers believe that this HDFN can cause anemia and usually worsens with second, third, and following pregnancies.
This, they believe, could have led to a decrease in the number of Neanderthal children.
“Analyses of blood group systems of Neanderthals and Denisovans contributed to a better understanding of their origin, expansion, and encounters with Homo sapiens,” the report read.
Although this could have also happened as a result of sexual relationships solely between Neanderthals, the risk of HDFN is reported to be higher in cases of sexual relationships between human ancestors and Neanderthals.
“These elements could have contributed to weakening the descendants to the point of leading to their demise, especially combined with the competition with Homo sapiens for the same ecological niche,” the report claims.
While the disorder is considered to be extremely rare in human species now, it is considered to be common in Neanderthals as the species’ gene pool is very limited.
“The fact that these forms of genes were detected in individuals separated by 4,000km and 50,000 years suggest that this genetic peculiarity and the risk of anaemic foetus would have been quite common amongst Neanderthals,” Stephane Mazieres, a lead author on the research from Aix-Marseille University was quoted saying by the Daily Mail.
Who were Neanderthals:
Neanderthals were humans like us, but they were a distinct species called Homo Neanderthalensis.
Neanderthals had a long, low skull (compared to the more globular skull of modern humans) with a characteristic prominent brow ridge above their eyes. Their face was also distinctive. The central part of the face protruded forward and was dominated by a very big, wide nose.
Species: Homo Neanderthalensis
Lived: from about 400,000 to 40,000 years ago
Where: across Europe and southwest and central Asia
Appearance: large nose, strong double-arched brow ridge, relatively short and stocky bodies
Brain size: at least 1,200cm3 to 1,750cm3
Height: about 1.50-1.75m
Weight: about 64-82kg
Diet: meat, plants and fungi, shellfish when available
Species named in: 1864
Name meaning: ‘human from the Neander Valley’