And it’s all in the “how one measures.” The laughable idea that similarly-functioning DNA sequences mean two organisms have the “same gene” is…laughable.
Generally, that kind of language is used to reassure the naive that all humans are basically the same, with the same shared genetic pool, about equally distributed among all populations. And that’s nonsense.
A “gene” is simply a convenient nickname for a sequence of DNA thought to have a fairly identifiable function. But two “genes” that “are the same” because the same nickname is applied to a generally-similar DNA sequence in the same location may in fact be markedly different functionally even even a single base is different in the chain.
It’s those gene variants that vary in frequency by gene pool by population by historic migrations in human populations. You might, for example, argue that all humans have the “same gene, microcephalin” but the frequency of the haplogroup D variant of MCPH1 would vary markedly by population even at so coarse a level of grouping as africans v out-of-africans.
WRT to the 2-4% Neanderthal gene introgression in (most) non-africans, that is a huge percentage of archaic gene variants to be present so long after introgression.
Yet another point is that quantity of variants which are different is not necessarily much of a measure. A handful of significantly advantageous variants–and theoretically, even a single advantageous variant–can be enough to drive substantial outcome differences. Consider, for example, frequency of ACTN3 variants…
Couldn’t it also be indicative of a small founding population where virtually everyone in that population, in short order, got at least some Neanderthal DNA before it grew into a large population? Or, a larger population of which only those with some Neanderthal DNA survived for some adaptive reason the Neanderthal DNA gave? (I guess that 2nd scenario is really just a variant of the first one…)
I stand corrected. I got my data from memory and never intended them to be exact, so thanks for correcting. It doesnt really influence the point I was making tho.
As for the existence of mixed tribes: doesn’t seem likely, since, as mentioned, hybrids were probably mostly infertile, though I just read in that BBC article that female hybrids may have been mostly fertile. But still not enough basis for a mixed tribe.
Not only in captivity, they are perfectly happy to get funky with each other in the wild; in fact, one of the dangers of wild hoofed-ones populations is that mixed broods will produce mules, and male mules can end up leading broods… which will then produce no colts.
Not that I doubt you, but where are the places where wild horses and wild donkeys occur in the same areas? And what are the documented occurrences of interbreeding?
You know I guess there is no way to ever know for sure but given the history of the massacres committed throughout history and the fact that apparently there were a few different types of hominid species that lived at the same time as homo sapiens I always wonder if humans didn’t kill off these groups, maybe in addition to outcompete with them for resources.
It kind of sounds bad saying it but when I see some of these recreations of what we think some of these Neanderthal and other types of hominid lines looked like, its like some uncanny valley effect almost, because they are almost human, but not quite, some sort of proto-animal-human, I find some, but not all of those recreations disgusting on some innate level. Given how humans have killed those that were different throughout history it might not be that far a stretch, I can easily imagine that humans massacred these “others”. In all likelihood it was probably a combination of disease, competition for resources and maybe some killings as well. But apparently that didn’t stop humans and Neanderthals from getting it on.
This link seems to indicate that there is such a place in California and about 1% of the feral equines are horse/donkey hybrids. So apparently, yes, they’ll get jiggy with each other in the wild occasionally.
Both of your hypotheses are very seriously considered among scholars that study human evolution and it is almost certain that one or both of them is correct or at least partialy correct.
The study of human evolution is a very quickly evolving field. Even since I started on this board 16 years ago, experts have been proven wrong time and time again because of new research and discoveries. The fact that Neanderthals interbred with many existing human populations and still account for a surprisingly large amount of active genes is one of those and it starts to answer some questions but opens up many more. The real answer is that no one really knows the full answer yet but there are very large scale DNA projects working hard to unravel it all.
For a present day (1911) version of the last of his species google Ishi the last “wild” Indian. Of course not of a different species but psychologically he must have gone through a similar process. The whole thing is documented by A.L. Kroeber an anthropologist at Univ of Calif.
It also makes you wonder how the mixing happened - based on other social organizations…
Did they have common feasts and swap meets? Trade women between tribes? Catch solitary women alone by the river (Quest for Fire)? Conquerors from a rival tribe killed all the men and took the women?
You end up with the odd hybrid in the tribe, who then proceeds to distribute his genes into the tribe over subsequent generations. I presume the 3% to 4% means “…of genes where Neanderthal and HS genes would differ”.
I’m not sure. Maybe someone like Colibri can comment on that. Do we assume that only genes with base pairs that look like Neanderthal genes (as opposed to Sapien genes) came from Neanderthals? Or, since we often get genes in groups, would we assume that, for example, a “normal” looking gene that was sandwiched between 2 Neanderthal genes also came form our Neanderthal ancestors?
That is to say, most of the Sapiens/Neanderthal genes are identical, so given that I have Neanderthal ancestors, how would I know if any of those identical genes came to me from my Sapiens ancestors vs from my Neanderthal ancestors? If we could determine that that gene did come from one of my Neanderthal ancestors, does that count towards my nominal 2% Neanderthal genes, or do we ignore that one gene since it isn’t unique to Neanderthals.
