Researchers find neanderthal blood did not evolve and may have contributed to their demise
Researchers out of France have identified a unique antigen in red blood cells that may have contributed to the downfall of Neanderthals, according to an article in Live Science. These findings will be of interest to clinical laboratorians in hospitals who operate blood banks and blood bankers who do daily testing for blood groups and specific antigens.
“We showed that all Neanderthal shared the same blood group profile,” Mazières told Discover magazine. “Such low diversity is the signal of small populations.” He added, “the study shows how different blood types can help fight against infectious disease,” and that, “it emphasizes the importance of monitoring blood during both transfusions and pregnancies. The presence of some rare subtypes that originated with the Neanderthals but outlived them can lead to complications,” Discover reported.
Clinical laboratories and pathologists will appreciate these new findings, as this unique look into Neanderthal physiology illustrates how the importance of proper blood typing has endured throughout time.
“For any case of inbreeding of a Neanderthal female with a Homo sapiens or Denisova male, there is a high risk of hemolytic disease of the newborn. The condition can lead to jaundice, severe anemia, brain damage and death. This could have contributed to the demise of the Neanderthal population,” Stéphane Mazières, PhD (above), a population geneticist at Aix-Marseille University who led the study into why Neanderthals did not survive, told Live Science. Clinical laboratories that run blood banks and perform blood type testing will find the study results interesting. (Photo copyright: X, formerly Twitter.)
‘Incompatible Blood Type
Mazières’ team studied ancient genomes to further understand the evolution from Neanderthals and Denisovans to Homo Sapiens. Genome sequencing was used to look at blood groups from “dozens of people who lived between 120,000 and 20,000 years ago.” This uncovered “a rare blood group that could have been fatal to their newborns,” Live Science reported.
The rare blood type discovered was not compatible with either Denisovans or early Homo Sapiens. Additionally, the more diverse blood found in Homo Sapiens may have attributed to a more robust immunity, Discover reported.
“Nowadays, certain blood groups confer an advantage against pathogens such as cholera, malaria, one of the gastroenteritis viruses and, as we’ve seen recently, COVID. We can therefore imagine that the blood groups found in the first Sapiens may have equipped them with a new arsenal to face the new environments encountered as they spread across the world,” Mazières told Discover.
“The contribution of this study is twofold. It enlightens the expansion patterns of Homo Sapiens and recalls the anthropological effectiveness of genetic polymorphisms currently being surveyed for transfusion safety and pregnancy monitoring,” the researchers wrote in Scientific Reports.
Knowing a patient’s blood type is key to ensure immune system acceptance of the blood, leading to successful blood transfusions and preventing fatalities. Focus is given to Rh (Resus) factor’s positive and negative typing and on the antigens responsible for segregating A, B, and O blood types. In the case of Neanderthals, a look at red blood cells was key, Live Science noted.
Modern-day Rh incompatibility, which can occur when an Rh-negative woman is pregnant with an Rh positive fetus, can be discovered during pregnancy and treated with prenatal administration of lab-made immunoglobulin to prevent hemolytic disease of the newborn, Live Science reported. It’s a whole system of healthcare that was certainly not available in Neanderthal times.
“Neanderthals have an Rh blood group that is very rare in modern humans. This Rh variant—a type of RhD, another red blood cell antigen—is not compatible with the variants the team found in the Denisovans or the early Homo Sapiens in their study,” Mazières told Live Science.
Looking Ahead
While this research may not change the way blood is handled today, the new findings serve as a reminder of just how important and varied antigens in human blood type can be and how significant the variances impact individuals. It also provides a window into how subtle differences shape the way civilization grows.
The complexity of red blood cells remains an area worthy of continued research, especially since many of these surface and internal antigens are passed down through generations, Live Science noted.
Also, study results may further the decades-long attempt to create artificial blood that has both an extensive shelf life and is accepted by the immune systems of many different patients. However, that will be a daunting challenge. Over the decades, blood bankers and clinical laboratory scientists have watched many attempts to develop artificial blood come close but fail to demonstrate safety while delivering benefits to patients.
Technologies developed by Pääbo to sequence Neanderthal DNA are being widely used in many clinical laboratory settings, including to study infectious disease outbreaks
Pääbo is considered to be the founder of paleogenetics. This field of science studies the past through examination of preserved genetic material found in remains of ancient organisms. It was his development of pioneering technologies that allowed for the genomic sequencing of Neanderthal DNA.
“[Pääbo’s] work has revolutionized our understanding of the evolutionary history of modern humans,” said German electrochemist Martin Stratmann, PhD, President of the Max Planck Society for the Advancement of Science (MPG), in a press release. “Svante Pääbo, for example, demonstrated that Neanderthals and other extinct hominids made a significant contribution to the ancestry of modern humans.”
“The thing that’s amazing to me is that you now have some ability to go back in time and actually follow genetic history and genetic changes over time,” Svante Pääbo, PhD (above), director of the Max Planck Institute for Evolutionary Anthropology, stated in a news conference, Reuters reported. “It’s a possibility to begin to actually look on evolution in real time, if you like.” Development of modern clinical laboratory techniques for identifying and tracking disease outbreaks have already evolved due to these findings. (Photo copyright: Max Planck Institute for Evolutionary Anthropology.)
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Comparing Neanderthal DNA to That of Modern Humans
Back in the mid-1990s, Pääbo and a team of researchers decoded relatively short fragments of mitochondrial DNA of a Neanderthal male. They discovered through their analysis that the DNA from the Neanderthal varied considerably from the genome of contemporary humans. This validated the belief that modern humans are not direct descendants of the Neanderthals.
Pääbo’s research team found nearly all (99.9%) of the Neanderthal DNA they studied to be heavily colonized by bacteria and fungi. That required them to create solutions for assembling the short components of mitochondrial DNA like a huge puzzle.
To accomplish this, the team had to:
Work under clean room conditions to prevent the accidental introduction of their own DNA into their experiments.
Establish more efficient extraction methods to enhance the output of Neanderthal DNA.
Generate complex computer programs that could compare the ancient DNA fragments with reference genomes of both humans and chimpanzees.
“Neanderthals are the closest relatives of humans today” said Pääbo in the press release. “Comparisons of their genomes with those of modern humans and with those of apes enable us to determine when genetic changes occurred in our ancestors. In the future, it could also be clarified why modern humans eventually developed a complex culture and technology that enabled them to colonize almost the entire world.”
Pääbo’s team succeeded in reconstructing their first version of the Neanderthal genome in 2010. Their comparisons between the genomes of Neanderthal and modern humans proved that the two groups had produced common offspring about 50,000 years ago and that this genetic contribution did influence human evolution.
The genome of modern non-African people still contains about 2% Neanderthal DNA.
“We have found around 30,000 positions in which the genomes of almost all modern humans differ from those of Neanderthals and great apes,” Pääbo added. “They answer what makes anatomically modern humans ‘modern’ in the genetic sense as well. Some of these genetic changes may be the key to understanding what distinguishes the cognitive abilities of today’s humans from those of now extinct hominids.”
Those with Neanderthal DNA More Susceptible to Severe COVID-19 Infection
Pääbo’s research also found that Neanderthal DNA may have affected the immune systems of modern people. During the COVID-19 pandemic, his work verified that individuals who carry a gene variant inherited from Neanderthals are more prone to severe forms of the illness than those who do not have that gene variant.
“We can make an average gauge of the number of the extra deaths we have had in the pandemic due to the contribution from the Neanderthals,” Pääbo said in a 2022 lecture, Reuters reported. “It is quite substantial, it’s more than one million extra individuals who have died due to this Neanderthal variant that they carry.”
Pääbo’s research team continues to develop new methods for reconstructing DNA fragments that are even more biodegraded, and which present in smaller amounts. Their ultimate goal is to investigate even older DNA and genetic material that is scarce due to climate conditions.
The DNA technologies pioneered by Pääbo to sequence Neanderthal DNA are being used widely in many clinical laboratory and research settings today. They include forensic science and the ability to collect DNA from human remains hundreds of years old to identify infectious disease outbreaks and study how today’s human genome has adopted new mutations.
Latest-generation DNA sequencing technology helped scientists achieve this feat
This spring, a particularly interesting milestone on the road to genetic medicine was achieved. The genome of Neanderthal man has been sequenced at the 1X level. It is a remarkable accomplishment by scientists from both the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and 454 Life Sciences Inc. , a division of Roche Holdings.
The final Neanderthal draft sequence is made up of three billion bases of Neanderthal DNA. This represents an estimated two-thirds of the entire genome. A research team has been assembled to evaluate and analyze the Neanderthal genome. Their findings may be published by the end of the year.
