Before I proceed, I’d like to indulge and share my moment of magical thinking, and admit I’d hoped to get some answers from the Neanderthal DNA on RhD disease. Sadly, there were no new answers, so I’ll proceed with the debunking for those few people who want science facts and not magical thinking.
When Paabo Savante’s team gave us our first glimpse into Neanderthal DNA, the first thing people who search for historical answers to the RhD deletion noticed, was two Neanderthal males had O blood type. This is all the facts some people needed to declare that Neanderthal interbreeding with humans, caused the RhD deletion. After all they pointed out, Neanderthals passed red hair, pale skin, and light-colored eye genes to Homo sapiens. Correlating eye and hair color to having Rhd doesn’t make sense, genetically, but this myth persists.
Dr. Marion Reed and Dr. Ian Shine (both authors of many books on blood types or genetics) stated in their book, The Discovery and Significance of the Blood Groups, that “blood type O gene is a variant of the blood type A gene. Thus, blood type O actually appeared later than the other ABO Groups.” Blood group A and B are dominant genes and blood group O is recessive. (See page 104) This fact can’t be disputed since our genetic DNA code was mapped in 2003.
Dr. Carles L. Fox, et. al (Genetic characterization of the ABO blood group in Neandertals) wanted to study the Neanderthal O blood. “The high polymorphism rate in the human ABO blood group gene seems to be related to susceptibility to different pathogens. It has been estimated that all genetic variation underlying the human ABO alleles appeared along the human lineage, after the divergence from the chimpanzee lineage. A paleogenetic analysis of the ABO blood group gene in Neandertals allows us to directly test for the presence of the ABO alleles in these extinct humans.” The Fox team concluded, “The genetic change responsible for the O blood group in humans predates the human and Neandertal divergence.” This means Neanderthals didn’t give us our O alleles.
Many scientific teams proceeded to crack the DNA code for Neanderthal man. An earthquake in evolutionary science occurred, and this feat gave us new information about disease-carrying genes the Neanderthals passed to us, like Crohn’s Disease, Diabetes Type 2, and Biliary Cirrhosis. So scientists are aware of what we received and didn’t receive from the Neanderthals. This isn’t to say new information won’t be discovered, especially in protein chemistry, in the future. For now, please look at table 2 in this ground breaking article-A Draft Sequence of the Neandertal Genome. It lists Amino acids changes that are fixed in present day humans, but ancestral in Neanderthals. What you get are the genetic markers, their position, and their description and function. No markers are listed for ABO or RhD.
A geneticist from Stanford, Dr. Barry Starr in 2013 pointed out that RhD deletion didn’t come from Neanderthals. (Read blog post) He asked another scientist, Dr. Bill Flegel of the National Institute of Health for his thoughts. Dr. Flegel stated in the blog post that RhD deletion occurred in Africa before modern man left in the migration wave out of Africa. Note Flegel has written many articles on RhD and interpreted a lot of genetic tests along the way.
Nova spoke with Paabo Savante, who opened up the field of evolutionary genetics, and other scientists, about the DNA discoveries of Neanderthal DNA (read Nova transcript). It also confirmed that the interbreeding between Homo Sapiens and Neanderthals resulted in Neanderthals passing their genetics to us, but Homo Sapiens didn’t pass any of our genetic code to them. I mention this because when the two species intermingled there is evidence found on the Y chromosome that male offspring of this mating were sterile, but because we have their DNA in us, we know female offspring shared it. In conclusion we knows Neanderthals lived 300,000 years before modern humans arrived on their turf, and the genetics they passed to us may have helped us survive.
If you liked this article, please share on your social media! If you have information to share please comment, I’d love to hear from you. I’m hoping now that evolutionary genetics has exploded that a scientist will soon be able to tell us what caused our Rh negative blood. My bet is still on a viral disease, what’s yours?