Yukon fossils represent a pivotal moment in evolution

[Minimalist]

then it must have also been powerful enough to create very widespread genetic bottlenecks in all sort of species everywhere in the world. We don't see strong evidence of widespread havoc around the world, only primates in Africa seem to suffer this bottleneck.

Precisely.

[Anomalocaris]

WHeather the cause was toba or something else does not change the fact that the bottleneck effect on homo sapien was there. whether the bottleneck event directly or indirectly caused the migration out of Africa also does not change the fact the genetic evidence not only supports OOA by a small group, it maps out the route routes the major present population took once the single small group left Africa and split up into different groups.

So the fate of neither toba theory nor the bottleneck effect can challenge the OOA hypothesis of non-african homosapien origin.

[reverendjeremiah]

As long as we are talking about fossils, this one could blow the Out of Africa crowd out of the water ... [snip rest]

As evidence builds, theories are refined or replaced. I am not particularly married to the out-of-Africa theory so it would not be too devastating to find out that it is wrong. It has never quite added up right for me anyway so I have always been open to a better theory. Thanks for the link to this.

Im not "married" to it either, but from what I have read, a good case has been made based on the shanty evidence we have that the "out of Africa" model will be king unless some GRAND evidence shared across scientific fields could be produced to the contrary.

[Minimalist]

Proponents of a theory always think they have met their evidentiary burden.

Hell, theists think they have with no evidence at all!

[Anomalocaris]

One should also clarify which specie is meant when saying "Out of Africa". I think a predominant OOA origin for modern HSS currently living in the rest of the world is well atested.

This reminds me of a argument I had with two Chinese biophysicists who were not actually practicing paleontologists, but who were otherwise well versed with evolution, molecular biology, gene sequencing, etc. They insisted that local population of homo erectus in China already exhibited mongoloid features half a million years ago, and therefore modern Chinese must have evolved in place from local homo erectus, and can't possibly be descendants of Africans. They pointed to a certain Chinese paleonotologist who had published to this effect as the defining authority on this subject whose word it is almost criminal to contradict. When I pointed out that many more Chinese paleontologists subscribe to the Out of African hypothesis of modern HSS, even Chinese, they were indignant. When I pointed out that a couple of Chinese paleontologists argued from fossil evidence that no morphologically recognizable mongoloid population existed before the end of last ice age, and that prior to that even the population that lived in confines of modern China exhibited generic morphological characteristics that were definitely homo sapien but hard to fit into any modern group, they became even more indignant. Well, meager evidence that has been discovered so far might suggest that, but she is absolutely certain that when more evidence has been found, the weight of evidence will point the other way. How she could have known this when the said evidence is not yet found, I asked. Look at us, we are not descendants of Africans, she said.

[Minimalist]

I think a predominant OOA origin for modern HSS

But now we must begin to ask ourselves if HSS is actually a separate species from HNS or HE? The fact that interbreeding between HSS and HNS has been shown is a blow to the separate species concept.

The Inuit



and the Watusi




are both HSS and are capable of interbreeding.

Who is to say that HNS was nothing more than an isolated tribal group off the main tree of HE which developed certain characteristics as a result of inbreeding? This is why we must find a source of HE dna.

I sort of think he



might well be grandpa.

[Anomalocaris]

It doesn't actually matter whether HN and HE outside of africa were technically capable of producing fertile offsprings with HS, Min. it doesn't even matter if there were already bonafide HS in euroasia prior to when OOA placed the first departure of HSS from Africa. The OOA hypothesis hinges on whether the current HSS population in euroasia predominantly descended from an migration of Bonafide HS out of Africa. Genetic evidence says it was.

As to the innuit and Watusi, you know well that is an emotive but disingenuous comparison. 1st. OOA deals with origin of HSS outside of Africa. Without knowing the specific genetic makeup of Watusi, who presumably came from inside of Africa, you don't know how their ancestors fit within the narrative of the OOA. 2nd, even so, you know well that genetically, innuit and Watusi are very close, having shared one common maternal ancester within about 120,000 years. Take away those adaptive morphological changes which can be shown to have very recently been forced by their present environmental conditions, what remains is also morphologically similar, far more similar than between either group and HN or HE.

As to our possible relationship with HE, the question really is not whether that was so. Some way or another HS descended from HE. The question is, if it were so, did it happen again and again after HS had already arisen. Here the morphological evidence argues against it. The Inuit and the Watsui may differ greatly in skin color, height, certain fine facial features, but they there are no traits such that, if an offspring were to possees something like an average of the features of his parent, that would by itself severely imperil his survival. Not so between HE and HSS. HSS possess a child growth pattern that is unique amongst primates. Unlike all other primates, we are born with our central nervous system morphologically already close to full development. We are not just big brained, we are born big brained. To make this possible, the pelvic girdles of HS females are also unique. Modern woman are wide hipped in comparison to HE woman because the birth canal must accommodate the passage of a full sized brain. If a HE woman were to attempt to give birth to a infant with a mix of HS and HE growth characteristics, the birth would likely be exceedingly difficult, probably killing both the mother and infant in the process. If a HS woman were to give birth to the same, the birth itself might be successful, but it seems unlikely the offspring would develop normally with his age peers, would likely die an outcast.

[Shell B]

As long as we are talking about fossils, this one could blow the Out of Africa crowd out of the water ... [snip rest]

As evidence builds, theories are refined or replaced. I am not particularly married to the out-of-Africa theory so it would not be too devastating to find out that it is wrong. It has never quite added up right for me anyway so I have always been open to a better theory. Thanks for the link to this.

I do not think it is impossible that convergent evolution may have happened in the span of human history as well. Why couldn't we have humans in Asia and Africa, evolving separately, but filling the same ecological niche? Obviously, unlike other convergent species, we have covered the globe, so there is no need for more than one human species on Earth any longer. However, that does not mean that it did not start that way.

You misunderstand the concept of convergent evolution. Convergent evolution deals only with superficial similarities like the shape of whales to those of the fish. The evolution of the genome of two different species never converge. The genes of whales did not, can not, grow more similar to those of the fish. No species will ever arise from a merging of the whale and the fish. It is impossible that homo sapiens descended from two or more extinct homo or pre-homo species. There can only be one species that is the direct ancester of homo sapien.

This fact is a unbreakable constraint that any theory of homo sapien origin must observe.

I think I made the mistake of saying human, when I mean human-like. I don't think we evolved from two species mating. I actually never said that. What I was saying that there is no reason that human (meaning human-like) creatures could not have evolved in two separate places. Then, we would have a confusing remains. Of course, the genome could be similar going back that far if more than one human species evolved from similar monkeys. That being said, I don't actually believe any of this. I am merely saying that it is not impossible that we will find/have found humanoid remains that are the result of convergent evolution. That doesn't mean they are our ancestors. I did not suggest that.

Furthermore, whales and fish are not an example of convergent evolution. Convergent evolution is like having mice in Australia and mice in North America that have evolved completely separately, but are similar because they fill the same ecological niche. Whales are mammals. Fish are fish. Not all fish, but many fish, do not fill the same niche as whales nor did they evolve in different ecosystems, unless we are talking freshwater fish or fish that live in the few areas of the ocean where whales do not dwell.

Sorry it took me so long to reply. I had forgotten about this thread.