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Memories of the 28th Century

Non-extinction of Neanderthals

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I have read many times that Neanderthals became extinct. That annoys me, because it is false. It may seem like a delicate piece of sophistry, but extinction is when a species, subspecies, or variety dies out, leaving no descendants. That is tied in with some people inaccurately referring to Neanderthals as a species; they are not a species separate from H. sapiens. This may seem like picking nits, but if we can get the details right, then we can better understand the whole picture.

Species are populations of animals or plants that can successfully breed with other members of the species, but there is no successful breeding between animals or plants that are not of the same species. There are genes in modern humans that were not part of the genome until there was interbreeding between Neanderthals and modern H. sapiens; that interbreeding was completely successful, because it produced fertile offspring through whom Neanderthal genes have been passed down to humans living now. If the Neanderthals had been of a different species, then those genes would not have been passed down. Since Neanderthal genes are still present among humans, Neanderthals did not become extinct; they interbred with and were absorbed into the larger mix of H. sapiens.

It appears that Neanderthals were a different race or sub-species; those two words are usually taken as synonyms, or Neanderthals might be a breed or variety of human. Those terms are broad and vague, and it might be a good idea to keep the relationship broad and vague.

Just to make it a little clearer that Neanderthals are humans, please note that according to "As of 2015, the typical difference between the genomes of two individuals was estimated at 20 million base pairs (or 0.6% of the total of 3.2 billion base pairs)." (see linked pages) The difference between modern humans and Neanderthals is less than the genetic difference between pairs of modern humans. That's just a bit of statistical evidence, but it shows that the difference from Neanderthals to us is very small. A few years ago, I wrote a post about having met people who could pass as Neanderthals or even H. erectus, which is a considerably larger difference, but H. erectus were still living within the last fifty thousand years for certain, and they may have survived until as recently as 20,000 years ago.

While Neanderthals and Denisovans were not separate species, they were separate races. In biology a race is a group of individuals within a species that is unlikely to mate with other of the species outside their race because of location, habits, or physical adaption. Races or subspecies (the two terms are usually used interchangeably) sometimes are evolving toward becoming separate species, or they can reconverge with the rest of the species, as happened with Neanderthals and Denisovans.

While applying the definition appears to make the matter perfectly clear, but among anthropologists there are "lumpers" and "splitters". The preference of the splitters probably is why some people call Neanderthals a separate species, but whether they were a race or a species is of little importance until one asks how they were related to us.

If Neanderthals were of a different species, then they could not have provided genetic material that went into the human genome, because they could not have produced fertile offspring by mating with humans. But several percent of the present-day human genome are thought to be derived from Neanderthals, so they had to have been of the same species as modern humans.

The information about species, Neanderthals, etc. in this post is quite elementary. I wonder why journalists who write about evolutionary anthropology are ignorant of this information.



Notes:

"To understand the genomic differences between present-day humans and Neanderthals, the researchers compared subtle differences in the Neanderthal genome to the genomes found in DNA from the five people, as well as to chimpanzee DNA. An analysis of the genetic variation showed that Neanderthal DNA is 99.7 percent identical to present-day human DNA, and 98.8 percent identical to chimpanzee DNA. Present-day human DNA is also 98.8 percent identical to chimpanzee."
https://www.genome.gov/27539119/2010...nome-sequenced


"As of 2015, the typical difference between the genomes of two individuals was estimated at 20 million base pairs (or 0.6% of the total of 3.2 billion base pairs)."
https://en.wikipedia.org/wiki/Human_genetic_variation

"differences in types of genetic variation and how they ... 23 chromosome pairs. 3.2 billion base-pairs (A,C,G,T). ~20,000 genes ... A recent study sequenced 2,504 individuals and ... more bases: the typical genome contains an estimated 2,100 to. 2,500 structural variants, affecting ~20 million bases of sequence."
http://www.biostat.washington.edu/si...0for%20web.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1893020/

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