Here is a long reply to Glenn's post re the alleged Neandertal
hybrid and the Out-of-Africa Hypothesis (OoAH), split into two
parts because of size.
My reply features excerpts of a reply from Dr Chris Stringer,
who I wrote to with Glenn's allegations about him not having an
open mind, and with Glenn's claims about the OoAH being threatened
by this alleged Neandertal-Modern Human hybrid and this fossil's
"muscle insertion" being uniquely diagnostic of Neandertals.
Dr Stringer: 1) refutes Glenn's allegation about him not having
an open mind; 2) rejects Glenn's claims about the OoAH; and 3) points
out that Glenn is wrong about this fossils's muscle insertions
being uniquely Neandertal.
I call upon Glenn to live up to the high standards of conduct
that he enjoins on other Christians, and publicly retract his
baseless allegations about Dr Stringer. It would be nice if
Glenn also retracted or moderated his claims about the OoAH and
this fossil's muscle insertions.
Steve
On Thu, 24 Jun 1999 21:00:10 -0500, Glenn Morton wrote:
>SJ>No doubt. But the fact is that the "other reports" weren't "bad" for
>>the Out-of-Africa hypothesis (OoAH) side either. But this report is a
>>little better for it.
GM>Actually you are incorrect here. ANY hybrid is a threat to the extreme
>Out of Africa proponents like Stringer.
On the contrary, it is *Glenn* who disagree is "incorrect here" about
Stringer being an "extreme Out of Africa proponent. Stringer has said
publicly he could accept that this alleged N-MH fossil was a hybrid. That
doesn't sound like an extremist to me.
In fact I wrote to Dr Stringer an included some of Glenn's assertions, and
he has kindly answered them, showing that Glenn is way off the mark on
just about everything. I will include extracts from his reply to each point
raised by Glenn, prefaced by "CS>":
CS>I have NEVER said that Neanderthals could not have interbred with modern
>humans (e.g. see Stringer & Gamble pp. 72, 193; Stringer, C.B. 1992
>Replacement, continuity and the origin of Homo sapiens. In G. Brauer and
>F.H. Smith (eds) Continuity or replacement? Controversies in the evolution
>of Homo sapiens. Balkema: Rotterdam, pp. 9-24; Stringer, C.B. and Brauer, G.
>1994 Methods, Misreading, and Bias, American Anthropologist 96: 416-424),
>but did want to see good evidence for it having occurred on any detectable
>scale. However, the mitochondrial DNA results of Cann, Stoneking & Wilson
>ten years ago certainly suggested there COULD have been complete replacement
>of archaic humans by "Out of Africa" moderns.
CS>I would stress again that I am
>keeping an open mind about this, and have tried to say that to every
>journalist who interviewed me, but they don't always want to hear that, and
>much prefer to polarise their stories! Best, Chris Stringer
If "ANY hybrid is a threat to...extreme Out of Africa proponents" and
Stringer is an OoAH proponent who is willing to accept that this find is a
hybrid, then by Glenn's definition, Stringer isn't an "extreme Out of Africa
proponent"!
The fact is that only if hybridisation was common would the OoAH be
threatened and the MR/RCH supported. If hybridisation was comparatively
rare, then the OoAH would need little or no modification.
GM>They believe
>that Neanderthals were so different that they were an entirely separate
>species. And if a separate species, then by definition,
>Neanderthals and humans could not interbreed and produce fertile
>offspring.
This depends on one's definition of species. Some taxa classed as
separate species can interbreed, but rarely do in nature, as Glenn
himself says at the foot of this message:
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GM>Coyotes and wolves/dogs split 1 million years ago and they can still
>produce fertile offspring.
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The true defintion of species is a bit more complex, as Stringer himself
points out in his excellent book, African Exodus:
"In fact, a species is usually designated as a group of
Organisms which normally do, or could, interbreed to produce fertile
offspring (that is, ones which can in turn successfully breed). Closely
related, but different species, may interbreed, but either this is not
their normal behaviour, or the hybrid offspring cannot reproduce in
the long term - such as the mule, the sterile offspring of a male
donkey and female horse. Even when they meet, closely related
species show differences in behaviour, physical appearance or scent,
which deter interbreeding." (Stringer C., & McKie R., "African Exodus,
1997, p51)
If it turns out that Neandertals and modern humans *could* have
fertile offspring but rarely did so, then they could still be classified
as a closely related but different species. Dr Stringer agrees with this:
CS>And the existence of hybrids would not even disprove the idea of some
>anthropologists (including me) that the Neanderthals were probably a
>different species from us. Such a species would have been very closely
>related to us genetically, and many such species of mammal do hybridise -
>for example, lions and tigers, and dogs and wolves. The real question would
>be whether the species merged, and we have no evidence of that for the
>Neanderthals and Cro-Magnons. Both fossil and recent DNA studies (so far!)
>support the view that Neanderthals were not our ancestors. The limited
>amount of Neanderthal DNA recovered to date is quite unlike that of people
>alive today, and extensive genetic sampling of present day Europeans has so
>far found nothing resembling it.
>SJ>Glenn makes it sound like its an uphill battle. I don't see it that
>way at all. Every round to date has been won by the Out-of-Africa
>hypothesis, and if this turns out to be a Neandertal-CroMagnon hybrid,
>it will be a minor exception that proves the rule.
GM>No exception proves the rule. All exceptions DISPROVE the rule.
Not really. Behind this wise saying is the truth that a rule that has only
minor exceptions is established as a *rule*. It may not be a *law* of
nature, but it is a *rule*. And the rule that this N-MH hybrid would
establish (if it holds up as a hybrid), would be that certain Neandertal
characteristics would be detectable if there was interbreeding with Modern
Humans. If such characteristics are rarely detected, then it is *devastating*
for the Multiregional/Regional Continuity Hypothesis (MR/RCH), which
posits that such mating should be common, but leaves a slightly modified
OoAH as the only game left in town.
This may not have dawned on the MR/RCH yet, but it will soon dawn on
the OaAH proponents, if it hasn't already! If this really is a hybrid, then all
the vague claims that the MR/RCH make about Neandertal characteristics
in modern human fossils elsewhere, could be tested against the
characteristics of this fossil. If they didn't have them, then the MR/RCH
advocates would have to chose between this fossil and those other fossils.
In fact, I predict that if this really is a hybrid, then it will turn out to be the
last gasp of the MR/RCH!
Indeed, the very song and-dance that MR/RCH advocates are making about this
fossil, shows that the MR/RCH does not have much real evidence at these other
sites.
>SJ>...If there is any "tooth and nail" fighting it is on the
>>side of advocates for the Multiregional/Regional Continuity (MR/RCH)
>>hypothesis. The OoAH is now firmly established, and it is unlikely that the
>>MR/RCH will make much of a dent in it. If this fossil turns out to be a
>>hybrid, it will show how rare the interbreeding was. And since most (all?)
>>hybrids are sterile, it would mean that neandertals contributed nothing to
>>the modern human gene pool.
GM>You are a bit behind the times Stephen.
When Glenn starts casting aspersions on his opponents (which happens often),
it is often a smokescreen to cover up for his own position's weakness. In this case it is to divert attention
fromn my point above that rare interbreeding and sterile offspring, would mean that neandertals contributed
nothing to the modern human gene pool.
Stringer confirms my point:
CS>*IF* the Lapedo skeleton is that of a hybrid, it would answer the first
>question in demonstrating that such interbreeding did take place, but it
>cannot answer the question of how common such matings were, whether the
>hybrids were fertile, whether their genes ever penetrated into the early
>modern populations, and what was the eventual fate of such genes. If a
>hybrid was the product of Neanderthal female-Cro-Magnon male mating, for
>example, the child might have remained with its mother's (Neanderthal)
>group, and its mixed genes would not necessarily spread into modern
>populations; a hybrid, even if fertile, may have been shunned as a potential
>mate by the mainstream populations; subsequent population crashes at the
>Last Glacial Maximum, about 20,000 calendar years ago, could have eliminated
>any surviving hybrid genes etc. etc.
GM>Out of Africa (OoA)
>hypothesizes that all modern humans are descended from a
>group of people who came out of Africa about 120,000 years ago.
My understanding is that it *began* 100,000 years ago:
"This date, of course, perfectly accords with the idea of a separate recent
evolution of Homo sapiens shortly before it began its African exodus about
100,000 years ago." (Stringer C. & McKie R., 1997, p114).
The Cro-Magnon's are thought to have exited Africa only 50,000 years ago:
"Of course, there was clearly no single exodus, no one triumphant army of
early hunter-gatherers who were led Out of Africa towards a new world by
a palaeolithic Moses. Instead, our exodus would have occurred in trickles
as our ancestors slowly seeped out of the continent, expanding their
hunting ranges and taking over new territory. Marta Lahr and Robert Foley
of Cambridge University believe they can reconstruct one such expansion
that spread eastward out of the Horn of Africa about 80,000 years ago. Its
populations diversified as they moved to eastern and south-eastern Asia,
Conning the region's modern 'races'. A later dispersal, about 50,000 years
ago, infiltrated North Africa, western Asia - and Europe, in the form of our
old friends, the Cro-Magnons." (Stringer C. & McKie R.,1997, p153)
GM>These
>people are hypothesized to have been incapable of
>interbreeding with H. erectus and Neanderthals and archaic H. sapiens.
If doubt that any OoAH advocate has said that these modern humans were
"incapable" of interbreeding with these other hominoids, because that could
never be proved. What they do say is that they did not *normally*
interbreed with them:
"With an absence of ancient mitochondrial DNA in people today, the study
showed our ancestors must have emerged out of Africa and completely
supplanted, without any interbreeding, existing populations of other human
lines, an extreme form of replacement that was not an essential of the
original African Exodus model put forward by scientists like Chris Stringer
and Gunter Brauer. This allowed some, limited interbreeding." (Stringer C.
& McKie R., 1997, pp122-123)
Thus if it turns out that there was some rare interbreeding, then the OoAH
is still OK. But the MR/RCH requires that interbreeding be *common*.
GM>Modern men, in this view totally replaced all earlier
>populations.
Agreed. But this could still be done if interbreeding was rare.
GM>A big piece of the data supporting this view was that
>mitochondrial DNA pointed to a common ancestor about
>200,000 years ago.
While the OoAH is supported by Wilson et. al's Mitochondrial Eve
hypothesis, it is not dependent on it:
"Eve was popularly associated, in many people's minds, with the Out of
Africa theory - a connection that the multiregionalists specifically, and
misleadingly, tried to reinforce. (In their Scientific American paper, Thorne
and Wolpoff continually referred to the ideas of Stringer, Brauer, and the
others as the Eve hypothesis, despite the fact that the former group had
developed their Out of Africa model on fossil evidence and merely viewed
the genetic study by the Berkeley group as a provider of welcome support.)
The fall of one therefore seemed to imply the fall of both. In fact, the latter
retains a ruddy sheen of intellectual good health, for it does not depend on
the work of Wilson, Cann and Stoneking." (Stringer C. & McKie R., 1997, pp124-125).
GM>Paternal inheritance of mtDNA has been proven and
>this means that Mitochondrial Eve is now placed at
>400,000 years ago, long before the out of Africa hypothesis believes
>that modern humans came out of Africa. THis means that
>Eve was an H. erectus or an archaic Homo sapiens, (of which Neanderthal
>is a regional variant).
>http://abcnews.go.com/wire/World/Reuters19990310_1097.html
The link that Glenn provides no longer works. My understanding is that
paternal inheritance of mtDNA is far from having been proved. It is well
known that paternal mtDNA does occasionally pass over into the fertilised
cell, but that does not mean it survives into future generations.
Besides this article Glenn cites wrongly confuses the Mitochondrial Eve
hypothesis with the OoAH.
GM>Secondly the OoA has taken a BIG hit with the hybrid.
Not really. Here is what Chris Stringer said in his email:
CS>*IF* Trinkaus's observations and interpretations are accurate (see above for
>the main alternative explanation), this would be the first good evidence of
>such a hybrid, and therefore of the greatest interest. However, claims that
>this discovery completely revolutionises our view of the Neanderthals or
>somehow invalidates the "Out of Africa" theory are wide of the mark. We can
>trace the evolution of the Neanderthals as a separate line for at least two
>hundred thousand years in Europe, and the evolution of our own line in
>Africa over a similar time scale. Most anthropolologists and almost all
>molecular anthropologists accept that modern humans originated in Africa and
>dispersed from there during the last 100,000 years. The debate has centred
>more recently on the question of whether there might have been interbreeding
>with people like the Neanderthals during the dispersal phase, and whether
>such hybrid genes could be found today.
First it has yet to be shown that it *is* a hybrid. Second if it is a hybrid but
only a rare exception then it supports the OoAH. The alternative MR/RCH
needs hybrids to be *common* if the entire Neandertal population was
absorbed into the ancestors of modern day humans.
Besides, Glenn here contradicts himself. Earlier he said that "ANY hybrid is
a threat to...extreme Out of Africa proponents." This implies that there is a
normal, non-extreme OoAH which would not be threatened by one or a
small number of hybrids.
GM>While you
>continue to cite your own opinion, it would be nice if you
>could show disproofs of the mtDNA paternal inheritance instead of just
>spouting your opinion which is based upon nothing
>more than your epistemological need for this not to be true.
I don't need to prove or disprove the "mtDNA paternal inheritance" claims.
First, it has yet to be shown that paternal mtDNA has any last inheritable
effect. Second, even if it did, it would no bearing on the OoAH. Glenn has
already pointed out that the OoAH claims that "all modern humans are descended from a
group of people who came out of Africa about 120,000 years ago." Therefore
the OoAH would be unaffected if it turned out that modern humans had a last
common mitochondrial ancestor 400,000 years ago.
GM>This child
>has Neanderthal muscle insertions. The only way to get
>them is via genetics. NO modern humans have these characteeristics.
The article does not actually say that the has Neanderthal muscle insertions.
And it is false that no modern humans have such muscles insertions. Here is
what Stringer said:
CS>Second, there are no muscle features of the child so far
>described which are unique to Neandertthals and could not be matched in a
>robust modern child.
Even Trinkaus says that modern humans can share "the anatomical
characteristics of Neandertals":
"Anatomically, the Neandertals are quite similar to ourselves, having a
skeletal arrangement identical to ours...Rare individuals among modern
humans may share one, or even a few, of the anatomical characteristics of
Neandertals" (Trinkaus E. & Shipman P., "The Neandertals," 1993, p412)
>SJ>>Presumably they were all MR/RCH advocates. I would be more impressed
>>if any OoAH people switched camps on the basis of this evidence.
GM>Why, you won't switch camps regardless of how many people tell you that
>your position is wrong. Just tonight you said that multiple people
>criticize you for the same thing. have you considered taking the hint?
I take this is just another attempt by Glenn to divert attention from
the weakness of his position, so I won't take the bait!
>GM>As to the rejection of Schwartz and Stringer, that was almost to be
>>>expected. If Chris Stringer and Jeffrey Schwartz accepted it, almst
>>everything they had ever written in their careers would be wrong.
>SJ>Not really, in the reports I have seen Stringer was prepared to
>>accept it if it is confirmed...even if this was a Neandertal-
>>CroMagnon hybrid, it would make no difference to the main lines of
>>the OoAH.
GM>First, saying you will have an open mind is different than having one.
Obviously, but unless Glenn took mind-reading as a double-major with his
Geophysics degree, we must assume that when Stringer says he has an
open mind about this fossil, he really means it.
GM>Secondly, it does make a big difference to them.
This is just Glenn's unsubstantiated assertion. Stringer has said publicly
in press reports and in this email that one rare hybrid would not make a
difference to the OoAH. In fact there are some OoAH advocates who accept
some Neandertal interbreeding with Modern Humans before this hybrid:
"However, some of my friends and contemporaries are still not prepared to
write off the Neanderthals completely as potential ancestors. Gunter
Brauer, of Hamburg University, was also a strong early advocate of the
Out of Africa theory, but he still believes that some interbreeding between
Neanderthals and early Cro- Magnons occurred in the Middle East and
Europe, as demonstrated by the mixed features of the Hahnofersand skull
bone from Germany, and other fossils." (Stringer C. & McKie R., 1997,
p79)
[continued]
Steve
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Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ senojes@hotmail.com
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
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