It's a long way from a primate at 55 my to a human at 1 my or more recent.

Milford Wolpoff, the leading exponent of the many origins theory, has said he was wrong. The latest evidence puts our origin in Africa, and while there's always the possibility that new evidence will change things, the fossil sequence is now comparatively full and all the relevant ones are not only from Africa but from east Africa.

Harry is right. The origin of primates is far removed from the origin of man.

Mitochondrial DNA seems to have pretty nearly confirmed the out-of-Africa hypothesis for mankind.

Yes, that seems improbable.

It seems improbable that humans originated in Africa, or that they originated ONLY in Africa ?

It does appear as though the "African Eve" study has been discredited.

I am willing to accept that, every once in a while, something will happen to cause a cell's dna to change. Some small fraction of the time, that that will happen to a gamete. I can even accept that, some small fraction the time, that mutation will be expressed; some small fraction the time, that expressed mutation will be compatible with survival; some small fraction the time, that surviving mutation will actually be beneficial; some small fraction the time, the gamete containing that expressable, beneficial mutation will actually be the one to meet another gamete and form a zygote; some small fraction the time, that zygote will mate with another, and it's mutation will survive and breed true; and I even accept that, some small fraction the time, gametes with different numbers of chromosomes can mate and result in viable, true-breeding offsprings. I can even accept that possibility that, over billions of years, all these things could have happened the millions or billions of times that our current record of speciation requires (although I don't find it compelling).

But I refuse to believe that such a chain of events could happen several different times within geographically dispersed populations, resulting in the same mutation occurring and surviving, developing the same species independently several times.

Yes, but having accepted all the stuff you accept and given the rise of primates in numerous places and the variety of envionments conducive to humans, why wouldn't man have arisen in multiple locations?

Mr. Cohen;

It could be that humans are actually the cross breeding product of these multiple origins. I still find the origin of Cro-Magnon somewhat bizarre - they seem to just show up, as opposed to Neanderthals who appear to be much more of a continuation of what went before.

AOG -- The idea that we're the mongrel pups of different species is just evolution, isn't it? So, even if that's so, there has to be a first H. sapiens somewhere that we're all descended from.

OJ -- I'm not sure is I accept all that or not, I accept that it is a coherent hypothesis about the origin of man, if one is prohibited from assuming a Creator. It just makes clear that evolution's saving grace is that, over a long period of time, given sexual reproduction, it's hard to say that anything is such a longshot that it couldn't happen.

One thing I think you can say couldn't happen is that, in effect, there were five segregated 30,000 character numbers (with the restriction that each character could only be one of four integers), differing in as much as 2% of their characters, that these five numbers were each subject to random change, which takes the form of either one character being changed or long runs of characters being copied, pasted, or deleted within the number, that the length of each number could change, that each change was subject to a somewhat random verification process (survival) that took, on average, tens of thousands of years per change, and that in the end each number was identical.

Two other thoughts. First, if this happened, it would destroy the anthropic principle and make Fermi's Paradox overwhelming. Second, based on the mischief racists could make out of this theory, any scientist promulgating it should be hunted down and sacrificed for the greater good.

David:

Precisely. If the theory is correct it should have happened, but the implications are such that decent Darwinists have to deny it. Stephen Jay Gould's career, for example, is testimony to the political undesirability of his own scientific beliefs.

Similarly, folks like Jeff are forced to deny the obvious or deal with the results.

You misrepresent the theory, as usual.

The theory requires a founder event. Even if you took identical twins and separated them and put them in different environments, the theory does not call for one line to speciate just because the other does. Speciation is not merely internal, as you posit.

You really ought to study darwinism. You might find it interesting.

David:

They don't need to be identical, just close enough to interbreed. Lions and tigers are close enough to do that...

Mike: 1. That's why I say that this theory is a racist's laboratory. 2. I think that's AOG's point, but it requires that there be a single, original instance of H. sapiens somewhere. What I don't accept is the seperate evolution of H. sapiens in different, geographically isolated populations of precursor primates, regardless of how similar those precursor populations are.

Harry: I don't understand your comment. As far as I can see, the theory discussed here allows as possible a number of separate "founder" events. Next to the chance of that happening, the birth of unrelated identical twins would be a statistical lock.

Harry:

Yes, the utter uniqueness of founding events is what seems so improbable if species are as malleable as the theory requires.

David, I thought about saying couples of identical twins but did not, as I thought the point was clear enough. I guess I was wrong.

The point is, imagine (it never happens in nature) identical populations separated and placed in different environments. Darwinism does not, as Orrin fancies, propose that both will develop exactly alike. In fact, it says both will endlessly diverge.

This is easily observable among the Hawaiian fruit flies, whose populations are frequently separated (by, for example, migrating to another island). They do not then evolve similarly but differently, so that from one introduction there are now about 800 species, some more divergent than others.

Orrin makes another mistake in assuming that the theory requires species to meet some minimum level of malleability. Not so, as the example of the horseshoe crab famously demonstrates.

For a variety of reasons, some lines are more labile than others (horseshoe crabs at one end of the spectrum, fruit flies at the other).

Plants provide a rather more easily understood example of the pattern. The California tarweed in Hawaii speciated into 27 silverswords and greenswords.

Orrin is fond of saying "They're still flies/dogs, etc." but greenswords are not silverswords (one lives in permanent bog, the other in the driest desert), and neither is much like the tarweed, though enough alike for taxonomists to have guessed at the relationship. Sometimes taxonomists are wrong, but genetic matching proves they were right about the tarweed/silversword/greensword complex.

But we know precisely how malleable primates are and that they evolve into humans. It's improbable that they'd only do so in one place.

Michael:
I have to admit it has been a few years since I read up on the subject, but I thought mitochondrial DNA pretty much declared in favor of the out-of-Africa theory.

I take it I missed something. What?

Jeff, I suspect he meant that the simple-minded African Eve hypothesis has been abandoned. Both mitochrodrial and other DNA confirms the East Africa hypothesis.

They do not confirm that we all descended from one woman.

I don't have any idea how malleable primates are.

Jeff:

What Harry said.

The mtDNA studies used some pretty dicey assumptions to conclude that the one skeleton that they'd found was the ancestor of 90+% of the human race.

From what I remember reading, the out-of-Africa hypothesis was dramatized as "Eve," but really meant that all humans descended from a bottle-neck population of about 10,000 proto-humans.