Memories of the 28th Century

Within the last few days it occurred to me that I might have been mistaken; there might be more than one race within the human species, but skin color isn’t relevant. I guess the seed was planted when someone asked me about the Blood Type Diet. But the race determiner isn’t blood type; it is the Rh factor. Then I found a website that suggested this also http://rhnegativebloodsecrets.blogsp...nderthals.html .
This site makes some assertions that may not be supported by the evidence, but it’s hard to tell, and this site author also suggests that Neanderthals were a different species. It may be a matter of definition. “In biology, a species (plural: species) is one of the basic units of biological classification and a taxonomic rank. A species is often defined as the largest group of organisms capable of interbreeding and producing fertile offspring.” (http://en.wikipedia.org/wiki/Species) Males and females of different species cannot produce fertile offspring, but it is clear that Neanderthals and other types of humans produced fertile offspring, but it might be that there was a difference in blood type that restricted fertility of offspring. In biological terms, race is defined as “A population of interbreeding species that develops distinct characteristics differing from other populations of the same species, especially as caused by geographical isolation.” (http://www.biology-online.org/dictionary/Race)

If a woman who is Rh negative becomes pregnant by a man who is Rh positive, the fetus will be Rh positive. That situation can result in the woman becoming infertile after her first pregnancy, see linked article, http://americanpregnancy.org/pregnan...hfactor-2.html . There are some who assert that Neanderthals were Rh negative; although this is uncertain. If that is true, then Neanderthals probably started to diverge from other humans. Whether that is true, or not, Rh negative exists among all populations of humans; although it is a bit more common among Europeans, while Neanderthal genetic characteristics are not found in sub-Saharan populations, so it is doubtful that Rh negative was a Neanderthal characteristic’; it appears to have developed before Neanderthals separated from other humans. It is possible that there was a distinctly different populations in earlier time that was nearly a different species in which the Rh negative characteristic developed, but such a group has not been identified.

We still have the Rh Positive and Rh Negative, and people of different Rh factors are unlikely to interbreed very much, so they could be considered different species or races, if the two groups weren’t so completely intertwined. Eventually, the difference of Rh factor probably will disappear, but it probably will take a very long time, because being Rh Negative appears to be advantageous in fighting some diseases. In addition, Neanderthals had a superior immune system as a result of a different gene that gave them the HAL receptor, see linked article http://www.sciencedaily.com/releases...1122084405.htm This receptor is rare in Southern Africa, but it is shared by nearly all people of European or Asian origin.

Taken together, these genetic differences strongly suggest that there was a substantial amount of interbreeding between Neanderthals and the modern type, as this BBC article suggests. http://www.bbc.com/news/science-environment-14673047 It would be nice to be able to examine a large number of Neanderthals and the offspring of mating between Neanderthals and the modern types to determine how successful such pairings were. It is possible that there was an evolutionary advantage of male modern types and female Neanderthals that led to the Neanderthal male sex gene being lost, but this would run counter to the idea that the Rh factor was significant, if Neanderthals were Rh negative. Stirring in the matter of the Neanderthal MtDNA having been lost, and it looks like there was an advantage in there being female moderns with male Neanderthals.

There is a fair amount of information on the internet about the Neanderthal genome. That was completed a few years ago, but people are still coming out with additional analyses, but the weight of the information appears to indicate that there was much interbreeding between Neanderthals and moderns, and the offspring certainly were fertile, but there may have been limited fertility in some cases, which led to the sex chromosomes of Neanderthals being lost, even though genetic material for skin, hair, nails, etc. and for skin and hair color come from Neanderthals, and a common gene for immune response was also from them. Neanderthals had blood types A and O, but there is no sign of AB or B. There is no solid evidence for Neanderthals having been Rh negative, and the Rh Negative type has been around for a very long time, which makes its continued existence a little mysterious. If Rh Negative women looked peculiar, then it might have been bred out of the species, but those women look like anyone else.

My conclusion is that Neanderthals were a race of humans, but they were fully interfertile, so they were of the same species. As I understand it, the biggest problem that the Neanderthal genome project had was finding differences. Genetically there were a few differences, and those appear to have been adaptations to more Northerly climates. In appearance Neanderthals and moderns were in the same range. I have seen people who looked like Neanderthals. And they just looked like people. I also met a guy who looked like he could have been h. erectus; he looked a bit strange, but he was clearly human. There probably aren’t any pure-blooded Neanderthals around anymore, but some people think that the Basques are close, but I won’t touch that. http://www.washingtonpost.com/wp-dyn...042701501.html You can look into it, if you like. One could consider the Rh factor the marker of a different race, but that’s a matter of technical definition.

I guess I was looking for a reason to become a racist, but after looking at the evidence I have to admit that my earlier opinion probably is most accurate; the human race is the only race of humans.