Whadya mean, ‘original’ humans? Well, before they were taken out of the box, before we left Africa and mixed with Neanderthals.
Or to put it another way, do we know which human population has had the least amount of genetic drift/mutations?
I figured it would be populations in Africa, what with environmental factors being more or less the same (or so I’m assuming), but it turns out that Africa is one of the most genetically diverse regions on Earth, oops. Any best guesses? Does the question make sense or has genetic variation from ancient populations been pretty much equal in the modern populations that followed?
Genetic drift IIRC is a side effect of time. Africa would have the largest diversity because the multiple groups that didn’t leave Africa are all in their own corners, lightly stirred, and drifting. Collect all the African inhabitants, try to backdate them, and you’ll have a pretty good picture.
If one small group leaves Africa, they drift too. But everyone beyond the Red Sea probably only drifts from that one group, does not include the other diverse groups who stayed behind in Club Congo. When the group that left Siberia for North America set sail (by foot?) then there would only be that limited group, and they would only accumulate 24,000 years or so of diversity.
So I assume diversity reflects the size and variety of the initial group, plus the amount of time to drift, modified by changed environmental pressures - skin color, etc.
But if we assume the least variation happens with the peoples associated with the African plains where we assume we mostly evolved to our present form(s)… That would be Kenya. No wonder a Kenyan is the most important most powerful person in the world today.
But seriously - original populations can be displaced, frequently are, if the displacement group has better tech - agriculture or domestication, better weaponry, adaptions, etc. So without a deep study of early human migrations about Africa, it’s hard to pinpoint your answer.
All human populations are “drifting” and “mutating” at the same rate.
Sub-Saharan Africans are the ones without an admixture of either Neanderthal or Denisovan, so those are arguably “closest” and most purely H. sapiens but really, aside from that, in some sense, we’re all equally divergent. Despite outward appearances, compared to our relatives the chimpanzees and gorillas we’re actually rather inbred.
For any given trait which shows variation, you can ask which version was the original one (and might even be able to answer that). But every population of humans will have the original versions of some traits and novel versions of others. I suppose you could ask for the population which has the greatest proportion of original traits, and that population probably would be one of the populations in Africa, but it’s a mistake to think of all of Africa as one population.
The premise is basically wrong. The assumption of the “molecular clock” for is that neutral or silent mutations accumulate at a steady rate with time in all lineages. Therefore all lineages should be more-or-less equally different from the original ancestor, at least genetically.
You can tell when one lineage separated from others by examining how many unique mutations have accumulated in that lineage. Lineages that split more recently will share more of their mutations - but the total number of mutations is the same.
Africa has the greatest genetic diversity of any area because humans have been diversifying for the greatest time there. All humans outside of Africa share an ancestry that is much more recent (with the exception of the Neanderthal and Denisovian genes they have picked up through interbreeding) and hence have less genetic diversity.
The human populations that from other humans the longest time ago, per genetic data, are the Khoi-San (“Bushmen”) of South Africa and certainPygmy groups of Central Africa. Note that these two groups look very different from one another. Although of similar antiquity, they have different hair, skin color, facial configuration, stature, and other features. Just because populations split from others a long time ago, doesn’t mean they are necessarily closer in appearance to the ancestral type. Each of these populations has been on its own evolutionary trajectory, independent of one another, and independent of other humans. They may each retain some ancestral traits, but overall there is no reason to suppose they have retained all of them.
Another example is Monotremes among mammals. They split from all other mammals longer ago than any other group. But the two surviving groups, the Platypus and the Echindas, are each highly specialized in their own way and look nothing at all like one another. Likewise, they certainly look nothing like the common ancestor of all mammals.
Supposedly the Soviet Russians found a young woman in a casket in the midst of a seam of coal some hundreds of feet down. She’d been placed in a casket made of metal of some sort that was well sealed and filled with a clear gel-like substance that had preserved the body perfectly. What had become a seam of coal had begun as a pre-tree “forest”, and I think the article said the casket had been set on a pedestal of some sort, and the ground had eventually collapsed under the pedestal and dropped the buried woman and casket some distance where the casket, girl and gel sat while the plants became coal. Later analysis showed that her DNA was identical to modern European humans. Oh yeah - her eyes, which were open, were blue. Now, if this was true and accurate, that would have been enough to put scientists in SEVERAL fields into life-long therapy… Of course the communists weren’t ABOUT to share any of this, and wherever they stashed the girl, there she remains I guess. With the pre-tree timeline and all, we’re talking 200,000,000 years here. Pre-dinosaur, too.
I’ve read over the years of as many as between twenty and thirty different kinds of human’s bones and bits having been found, and I’ve always had my doubts regarding evolution. On the other hand, Creationism isn’t something I’m ready to challenge OR accept either. We’re here and appear to have been here for quite some time, but NONE of the explanations on offer really satisfy, especially as some different types seem to have been genetic contemporaries. I’ve often wondered if we weren’t perhaps some immortal Some-thing’s / Some-One’s / Some-??'s idea of a celestial practical joke of some sort: “Hey, Lucifer! Come here and take a look at this! What IS that thing? It looks an awful lot like… Hmmm. Hey, have you been messing around in My workroom again?” Something along those lines… It’s a strange and wonder full Universe that may actually be a Multiverse of Multiverses. Perhaps there’s something about the nature of local spacetime (a VERY relative term) that dictates the essential physiognomy of “intelligent” beings. So the age-old conundrum of, “Who/what came first: Sasquatch or Billy Barty?” may not have the relevance some have always thought…
Maybe I’d better check on those mushrooms we had for supper last night before I take a nap…
Sorry, but this is complete and utter nonsense (and starting a post full of nonsense with “supposedly” doesn’t do anything to strengthen its credibility).
Moderating
Ian MacLeod, you’re new here, and may not be familiar with General Questions standards. This forum is for factual information, not for philosophical musings. If you want to discuss these topics, start another thread in Great Debates or IMHO. Don’t make other posts like this in the General Questions forum.
I read today (I think in Dawkin’s An Ancestor’s Tale that the last common ancestor of platypuses and echnidas (which look mostly like the union of hedgehog and anteater) most probably was of very similar form to the modern platypus, based on the fact that fossils of animals very much like platypuses have been found from before the two lineages split.
There was just a discussion here about the Sentinelese.
Not sure how close they would be to the “original” humans, but they have apparently lived in isolation for a long, long time.
Perhaps no people on Earth remain more genuinely isolated than the Sentinelese. They are thought to be directly descended from the first human populations to emerge from Africa, and have probably lived in the Andaman Islands for up to 60,000 years. The fact that their language is so different even from other Andaman islanders suggests that they have had little contact with other people for thousands of years.
Also, there might be other genes in any population that are the result of inbreeding. As I understand it, Denisovians are literally represented by fewer than 5 bone/teeth fragments–it’s a miracle we know about them, or could get enough genetic information to realize that a significant chunk of modern humans carried Denisovian genes. So who knows what other species of human might have flourished, interbred, and died out without leaving any trace (yet discovered)? So I don’t think we can be confident that African populations represent only genetic descent from a common ancestor.
Assuming that such other species interbred with H. sapiens sapiens, and left genes behind, might it not be possible to deduce their existence from genetic variations among modern human populations? Like, if there are a large number of genes common among the people of some region, but which are rare or unheard-of in the rest of humanity, and which show no obvious adaptive value for that region, might not the simplest explanation be that those genes come from a separate species that lived in that region?
We can be reasonably confident, primarily because Africa never allowed for easy isolation. Once the first humans evolved, we almost certainly spread by interbreeding with our direct Homo erectus ancestors rather than by aggressively displacing them. That process would have happened throughout Africa, meaning that humans carried any genes from African erectus populations as they went, and thoroughly mixed them across the continent. Current theory suggests that H. erectus was probably the only other hominid alive in Africa at that stage, but there could have been others, and they would have been incorporated in the same way
So while there certainly *were *other hominids in Africa at the time that we emerged and we certainly were interbreeding with them, we were so successful that by the time we’d covered the whole continent we had incorporated all their genetic material.
That’s what we mean when we say that African populations have a common descent. Not that the pre-exodus Africans were all descended from one individual or group, but that they had thoroughly blended all the groups to the point that everyone in Africa had the *same *ancestors within the past 100, 000 years. IOW if you drew the family tree for that period, there would be no branches because all branches of the the H erectus tree were fully incorporated on every branch of the sapiens tree.
In contrast of you drew the family tree for extra-African populations, a few people would throw up Neanderthal ancestors, and the siblings of *those *Neanderthals wouldn’t be integrated onto any branch of the sapiens tree.
Except modern Kenyans are not the original indigenes. Most Kenyans are Bantu (West-Central Africa) or Nilotes (Nile Valley e.g Sudan) The Maasai, for instance, only arrived in the 17th-18th centuries, the Kikuyu probably around the end of the first millenium BCE.
That’s a bit misleading since all non-Africans can claim to be “directly descended from the first human populations to emerge from Africa”. The important thing is the genetic isolation, which most of us non-Africans can’t claim to the same degree.
But keep in mind that Australian Aborigines also seem to be an ancient lineage that has mixed very little (until recently, of course) with other populations after having left Africa.
The “original H. sapiens”, though would be about 200,000 years old and any populations that left Africa would be much, much younger. More like 60,000 years old.
There was a serious bottleneck in human population about 70,000ya. Some attribute this to a volcanic eruption and subsequent climatic effects. I often wonder if some major evolutionary mutation didn’t give one small tribe a massive advantage (abstract thought? Better speech?) and the ability the “replace” any competitors, thus spreading their genes around the world.
The more current thinking about the genetic bottleneck is much more complicated than that. The date has not only been pushed back, but the duration could have been much longer than previously thought, too.