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Author Topic:   New Type of Ancient Human Found—Descendants Live Today?
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003
Member Rating: 8.7


Message 181 of 209 (624816)
07-20-2011 6:40 AM
Reply to: Message 180 by Jon
07-19-2011 1:28 PM


Re: New evidence
Rubbish, this changes nothing. Every argument we've made through the thread still holds.
The multi-region hypothesis is still plain wrong. The Out of Africa hypothesis continues to be broadly correct, we just now know it's not the entire story.
This doesn't make it wrong. The Central Dogma is not entirely correct, sometimes genes do from RNA to DNA, but that doesn't mean it's not a broadly correct description of how genes produce proteins. Pretty much every major, or minor, scientific theory isn't the whole story; this doesn't make them wrong, it makes them not the whole story.

This message is a reply to:
 Message 180 by Jon, posted 07-19-2011 1:28 PM Jon has not replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 182 of 209 (624874)
07-20-2011 1:36 PM
Reply to: Message 180 by Jon
07-19-2011 1:28 PM


Colors in a Mosaic
Hi, Jon.
I'm glad you responded.
Jon writes:
Anyone still attempting to hold to anything even resembling a strict OOA model is no longer doing science.
Melodrama aside, I think I can largely agree with the sentiment of this statement.
-----
Jon writes:
The authors apparently want to interpret the findings as pointing to an early one-off admixture consistent with a single migration event. However, it is difficult to understand how this can be reconciled with 'a mosaic of lineages of different time depths and different geographic provenance'.
I don't find it difficult to reconcile at all. Here is a link to a photo of a simple mosaic. This demonstrates that, even within a mosaic, there are frequently dominant patterns. For instance, I would have no qualms about calling this mosaic blue, even though there seem to be a couple of tiles in the mosaic that are white.
These authors are saying that, even though the bulk of the evidence suggests a pattern of blue tiles, they have uncovered at least one white tile. They go on to say that, despite this, the mosaic still rather appears to be blue. From my standpoint, this seems a relatively uncontroversial thing for them to say.
-----
Jon writes:
On top of this, these findings verify a prediction of the MH model and are supported by the OOA model only through the introduction of further ad hoc explanation.
I find it illustrative to point out that these findings also verify a tenet of the creationist argument concerning Neanderthals as degenerate humans. It is upon the bulk of the evidence, and not upon the singular anomalies, that the veracity of scientific theories are decided.
Edited by Bluejay, : No reason given.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

This message is a reply to:
 Message 180 by Jon, posted 07-19-2011 1:28 PM Jon has replied

Replies to this message:
 Message 183 by New Cat's Eye, posted 07-20-2011 1:54 PM Blue Jay has seen this message but not replied
 Message 184 by Jon, posted 07-20-2011 4:25 PM Blue Jay has not replied

  
New Cat's Eye
Inactive Member


Message 183 of 209 (624876)
07-20-2011 1:54 PM
Reply to: Message 182 by Blue Jay
07-20-2011 1:36 PM


Re: Colors in a Mosaic
Hi bluejay,
In Message 108, you wrote:
quote:
It seems silly to me to formulate a theory about biology---a field in which essentially all data sets are messy---so that it can't tolerate any deviance from 100% purity.
This seems like what the new MR-proponents are doing: they're arguing that any deviance from the most stringent interpretation of OoA is vindication of MR.
In light of new evidence, in Message 180, Jon writes:
quote:
On top of this, these findings verify a prediction of the MH model and are supported by the OOA model only through the introduction of further ad hoc explanation.
Anyone still attempting to hold to anything even resembling a strict OOA model is no longer doing science.

This message is a reply to:
 Message 182 by Blue Jay, posted 07-20-2011 1:36 PM Blue Jay has seen this message but not replied

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Jon
Inactive Member


Message 184 of 209 (624904)
07-20-2011 4:25 PM
Reply to: Message 182 by Blue Jay
07-20-2011 1:36 PM


Re: Colors in a Mosaic
This demonstrates that, even within a mosaic, there are frequently dominant patterns. For instance, I would have no qualms about calling this mosaic blue, even though there seem to be a couple of tiles in the mosaic that are white.
The specifics of where the genetic material in modern humans comes from is not really of concern to the model of MH. The main claim of MH is that the material will not all be found to have come from the same place. Even if a lot of it comes from one place (which is actually to be expected given the distribution of early humans), the MH model still holds.
These authors are saying that, even though the bulk of the evidence suggests a pattern of blue tiles, they have uncovered at least one white tile. They go on to say that, despite this, the mosaic still rather appears to be blue. From my standpoint, this seems a relatively uncontroversial thing for them to say.
What they are actually doing is stealing large parts of the MH model, labeling them OOA, and then declaring victory for the OOA model and defeat of the MH model.
I find it illustrative to point out that these findings also verify a tenet of the creationist argument concerning Neanderthals as degenerate humans.
And a strict OOA model would support a Creationist arguing that Neanderthals are part of Satan's plot to lead folk from the 'Truth'.
So we best not rely on creationists to steer us where we need go.
Jon

Love your enemies!

This message is a reply to:
 Message 182 by Blue Jay, posted 07-20-2011 1:36 PM Blue Jay has not replied

Replies to this message:
 Message 186 by Dr Jack, posted 07-21-2011 4:44 AM Jon has replied

  
Jon
Inactive Member


Message 185 of 209 (624905)
07-20-2011 4:32 PM
Reply to: Message 183 by New Cat's Eye
07-20-2011 1:54 PM


Re: Colors in a Mosaic
Hi bluejay,
In Message 108, you wrote:
quote:
It seems silly to me to formulate a theory about biology---a field in which essentially all data sets are messy---so that it can't tolerate any deviance from 100% purity.
This seems like what the new MR-proponents are doing: they're arguing that any deviance from the most stringent interpretation of OoA is vindication of MR.
In light of new evidence, in Message 180, Jon writes:
quote:
On top of this, these findings verify a prediction of the MH model and are supported by the OOA model only through the introduction of further ad hoc explanation.
Anyone still attempting to hold to anything even resembling a strict OOA model is no longer doing science.
I don't see that my argument is at all the same as what Bluejay said 'new MR-proponents are doing'. I don't think anything is a 'vindication of MR', this new evidence included.
I think this evidence verifies one of the MH predictions and forces the OOA model into ad hoc mode. Verifying predictions is one of the ways science strengthens theories. But it in no way vindicates them.
Jon

Love your enemies!

This message is a reply to:
 Message 183 by New Cat's Eye, posted 07-20-2011 1:54 PM New Cat's Eye has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003
Member Rating: 8.7


Message 186 of 209 (625004)
07-21-2011 4:44 AM
Reply to: Message 184 by Jon
07-20-2011 4:25 PM


Stop making up what the MRH says!
The main claim of MH is that the material will not all be found to have come from the same place. Even if a lot of it comes from one place (which is actually to be expected given the distribution of early humans), the MH model still holds.
Look at this (from Wikipedia). That is what the multi-regional hypothesis says! It claims that essentially parallel evolution occurred around the world, with a continuation of morphological features across tens of thousands of years. It's claim is not merely "that the material will not all be found to have come from the same place", but a much more complete claim of evolution occurring locally within human lineages.
That isn't what happened. Modern humans evolved in Africa, and then spread across the world replacing the local populations. Recent finds show that there was some small degree of inbreeding during that process but that isn't the MRH, it's OoA with a small modification in light of new evidence.

This message is a reply to:
 Message 184 by Jon, posted 07-20-2011 4:25 PM Jon has replied

Replies to this message:
 Message 187 by Jon, posted 07-21-2011 10:09 AM Dr Jack has replied
 Message 201 by DBlevins, posted 07-23-2011 2:02 AM Dr Jack has replied

  
Jon
Inactive Member


Message 187 of 209 (625071)
07-21-2011 10:09 AM
Reply to: Message 186 by Dr Jack
07-21-2011 4:44 AM


Re: Stop making up what the MRH says!
That is what the multi-regional hypothesis says! It claims that essentially parallel evolution occurred around the world, with a continuation of morphological features across tens of thousands of years.
Sounds more like you are describing polygenesis.
MH describes an interconnected evolving species; traits arise in various locations and spread throughout the rest of the world population.
... but a much more complete claim of evolution occurring locally within human lineages.
Not really. Central features are expected to flood the population as a whole, over time 'diluting' out regional differences which become less prominent as the species evolves.
This, of course, is according to Milford Wolpoff, the leading expert on, and proponent of, MH; but what does he know, eh? You found the Wiki!
Jon

Love your enemies!

This message is a reply to:
 Message 186 by Dr Jack, posted 07-21-2011 4:44 AM Dr Jack has replied

Replies to this message:
 Message 188 by Blue Jay, posted 07-21-2011 12:37 PM Jon has replied
 Message 198 by Dr Jack, posted 07-22-2011 4:10 AM Jon has replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 188 of 209 (625109)
07-21-2011 12:37 PM
Reply to: Message 187 by Jon
07-21-2011 10:09 AM


Re: Stop making up what the MRH says!
Hi, Jon.
Jon writes:
Mr Jack writes:
That is what the multi-regional hypothesis says! It claims that essentially parallel evolution occurred around the world, with a continuation of morphological features across tens of thousands of years.
Sounds more like you are describing polygenesis.
MH describes an interconnected evolving species; traits arise in various locations and spread throughout the rest of the world population.
Mr Jack isn't far off at all.
You've said a lot about a strict Out-of-Africa model. If you restrict your opponents to the strictest form of their model, isn't it only fair for your opponents to restrict you to the same?
The strict MR model is essentially what Mr Jack described. It states that regional populations of modern humans are genealogically continuous with archaic populations of the same regions. It argues that Europeans are essentially Neanderthals, Asians are essentially erectines (or Denisovans), and Africans are Homo sapiens sapiens. It differs from strict polygenism in that it allows genetic admixture between populations. But, it predicts that only those traits that are universally beneficial will have spread, while traits that are neutral or only regionally beneficial will not have spread.
Surely you can agree that this strict MR model does not hold up to scrutiny?
The version of MRH that is still held to today is not the same as the one I just described. Rather, it's a watered-down model with softer claims. It's essentially been reduced to the view that some unspecified amount of hybridization occurred between regional populations.
Essentially, once it was falsified in its strictest form, it was softened and adapted to cover all the middle ground between its original form and the competing out-of-Africa model. Despite this, you now criticize the out-of-Africa model for attempting to soften some of its claims in exactly the same way.
Even worse, you're attempting to argue that even a softened out-of-Africa hypothesis is invalidated by this new evidence of admixture. You seem to believe that any deviation from the strictest out-of-Africa model vindicates the stronger claims of the old multiregional model, something that modern MR proponents don't even claim.
I hope this provides some insight into why Mr Jack and I have gotten so irritated with you about this.
Edited by Bluejay, : No reason given.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

This message is a reply to:
 Message 187 by Jon, posted 07-21-2011 10:09 AM Jon has replied

Replies to this message:
 Message 189 by Jon, posted 07-21-2011 1:15 PM Blue Jay has replied

  
Jon
Inactive Member


Message 189 of 209 (625115)
07-21-2011 1:15 PM
Reply to: Message 188 by Blue Jay
07-21-2011 12:37 PM


Re: Stop making up what the MRH says!
If you restrict your opponents to the strictest form of their model, isn't it only fair for your opponents to restrict you to the same?
The 'strict' OOA model is simply the OOA model first proposed. No one is forced to hold to this strict version, especially given the evidence that has been found since its development. But they will then have to admit that their new version is just the older version supplemented with excessive ad hoc explanations.
Until all the ad hoc came about, strict OOA was the only OOA. And this is my point, the non-strict OOA is full of ad hoc.
The strict MR model is essentially what Mr Jack described. It states that regional populations of modern humans are genealogically continuous with archaic populations of the same regions. It argues that Europeans are essentially Neanderthals, Asians are essentially erectines (or Denisovans), and Africans are Homo sapiens sapiens. It differs from strict polygenism in that it allows genetic admixture between populations. But, it predicts that only those traits that are universally beneficial will have spread, while traits that are neutral or only regionally beneficial will not have spread.
This is not the theory described by Wolpoff and his ilk. This is not the theory I've been arguing for.
Surely you can agree that this strict MR model does not hold up to scrutiny?
What you call a 'strict MR model' has not been argued for in any serious academic setting for decades.
Essentially, once it was falsified in its strictest form,
The strict form you describe was falsified decades ago; the evidence that led to its falsification is the evidence that led to the development of the modern (actual) MH model.
Even worse, you're attempting to argue that even a softened out-of-Africa hypothesis is invalidated by this new evidence of admixture.
I never said anything was invalidated. This is a point I've made repeatedly regarding the scientific method, in this thread and in others.
It's really about time to stop misrepresenting me.
You seem to believe that any deviation from the strictest out-of-Africa model vindicates the stronger claims of the old multiregional model,
No; I don't. I've also spoken against this stupid notion of 'vindication' multiple times in this thread and others.
It's really about time to stop misrepresenting me.
I hope this provides some insight into why Mr Jack and I have gotten so irritated with you about this.
Probably because you both think I'm arguing for a position for which I am not actually arguing; a position which, you yourself admit, is 'something that modern MR proponents don't even claim'.
Of course, this debate is between you and me; so what other people argue regarding the two theories is irrelevant to the positions we present, which is why I've never held anyone here to the strict OOA model.
Jon

Love your enemies!

This message is a reply to:
 Message 188 by Blue Jay, posted 07-21-2011 12:37 PM Blue Jay has replied

Replies to this message:
 Message 190 by Blue Jay, posted 07-21-2011 3:02 PM Jon has replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 190 of 209 (625137)
07-21-2011 3:02 PM
Reply to: Message 189 by Jon
07-21-2011 1:15 PM


Re: Stop making up what the MRH says!
Hi, Jon.
-----
Jon writes:
I never said anything was invalidated. This is a point I've made repeatedly regarding the scientific method, in this thread and in others.
It's really about time to stop misrepresenting me.
I don't think I've misrepresented you. Perhaps my wording isn't the best, but this is hardly call for such exasperation from you. Here are some statements you made in this thread (all from the first page of "Jon posts only"):
post #10 writes:
The one-off African origin (of h. sapiens) proposed by OOA is simply not adequate for explaining this continuation of regional variations into present human linesat least some aspects of modern humanity must have evolved outside of Africa prior to 50-60 kya
Message 10
post #12 writes:
The replacement model is simply not accurate. This finding supports the notion that h. sapiens mixed with the earlier populations rather than merely replaced them. This is something predicted by MH; OOA proponents, on the other hand, have not been able to make these predictions, and have resorted to constant alterations of their model to explain new and contradictory evidencein similar fashion to the epicycles of geocentrism.
Message 12
post #24 writes:
Genetically speaking, modern sapiens are of African origin. I do not wish to dispute this. The issue is concluding physical origin on the basis of genetic origin. This is a conclusion I do not find overly validated by the information available.
Message 24
These are the viewpoints of yours that I am attempting to encompass when I say that you claim that OoA is invalidated. I apologize if my phraseology confuses and bothers you, but I would like you to admit that the irritation you are feeling is just about the semantics, and not about the substance, of the statement.
-----
Jon writes:
Bluejay writes:
You seem to believe that any deviation from the strictest out-of-Africa model vindicates the stronger claims of the old multiregional model...
No; I don't. I've also spoken against this stupid notion of 'vindication' multiple times in this thread and others.
It's really about time to stop misrepresenting me.
I think this is also little more than a semantic irritation on your part. What does "vindication" mean to you? To me, it means something akin to, "we've been saying it for a long time, and now you've finally been confronted with some evidence that forces you to acknowledge it." I think this is a very accurate representation of your position in this discussion.
And, as I explained, you have, in fact, argued that, since there is genetic evidence for admixture, there is no longer any reason to believe that an out-of-Africa migration ever happened (both again from only the first page of "Jon posts only"):
post #24 writes:
Genetically speaking, modern sapiens are of African origin. I do not wish to dispute this. The issue is concluding physical origin on the basis of genetic origin. This is a conclusion I do not find overly validated by the information available.
Message 24
post #26 writes:
OOA makes specific claims about population movements; these claims cannot be supported by the current evidence.
Message 26
If you're only making some parochial point about how my terminology doesn't accurately represent the tentativity with which you present your arguments, then I will make a concerted effort to amend my ways. I will refrain from using the words "invalidate" and "vindicate," as the discontent that seem to arouse exceeds their usefulness to my argument. I will instead use words like "untenable" or "unsupportable."
But, I think you're going too far when you claim I'm misrepresenting you.
-----
Jon writes:
Of course, this debate is between you and me; so what other people argue regarding the two theories is irrelevant to the positions we present, which is why I've never held anyone here to the strict OOA model.
While you have consistently made statements to this effect, your approach to the subject has not been in accordance with them. Your arguments have concentrated specifically on the migration component of out-of-Africa models. You argue that evidence of genetic admixture leads to the rejection of migration as a tenable explanation for anything. The result is that the available "theory space" is partitioned dichotomously into multiregionalism and strict out-of-Africa-ism.
Edited by Bluejay, : Correct "msg" tags: thanks, Jon (I've been away too long, I guess)

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

This message is a reply to:
 Message 189 by Jon, posted 07-21-2011 1:15 PM Jon has replied

Replies to this message:
 Message 191 by Jon, posted 07-21-2011 3:33 PM Blue Jay has replied

  
Jon
Inactive Member


Message 191 of 209 (625148)
07-21-2011 3:33 PM
Reply to: Message 190 by Blue Jay
07-21-2011 3:02 PM


Re: Stop making up what the MRH says!
You argue that evidence of genetic admixture leads to the rejection of migration as a tenable explanation for anything.
Not really. My argument is that there is no evidence that supports a migration. You quoted this sentiment from two of my posts:
quote:
Jon in Message 26:
OOA makes specific claims about population movements; these claims cannot be supported by the current evidence.
quote:
Jon in Message 24:
Genetically speaking, modern sapiens are of African origin. I do not wish to dispute this. The issue is concluding physical origin on the basis of genetic origin. This is a conclusion I do not find overly validated by the information available.
The migration model is unnecessary to explain modern genetic distributions.
The gene flow and regional continuity model is necessary to explain modern genetic (and morphological) distributions.
These recent findings (the one this thread was started about, the one you recently linked to, and others) have added support to the necessity of the latter model. As far as I'm aware, aside from the initial computer analyses, no findings have yet shown the former model to be necessary.
Or, when was the last time any extra evidence was found adding support to the necessity of the OOA model? The theory still seems to rest on those same outdated erroneous computer models upon which it was founded years ago.
Why it is still touted as a necessary explanation is beyond me.
Jon
BTW: Something's wrong with your message linkes; perhaps you meant to use the /msg/ tag instead of the /mid/ tag?
Edited by Jon, : No reason given.
Edited by Jon, : No reason given.

Love your enemies!

This message is a reply to:
 Message 190 by Blue Jay, posted 07-21-2011 3:02 PM Blue Jay has replied

Replies to this message:
 Message 193 by Blue Jay, posted 07-21-2011 4:38 PM Jon has replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 192 of 209 (625158)
07-21-2011 4:19 PM


Multiregional hypothesis
I have to confess that I'm thoroughly confused now as to what the multiregional hypothesis is and isn't, and about what evidence it would and wouldn't predict. I've been trying to do some reading from the main proponents of the multiregional hypothesis, and I found that my frustration with this particular group of people is only surpassed by my frustration with the work of Alan Feduccia and of the Intelligent Design movement.
Milford H. Wolpoff, one of multiregionalism's strongest proponents from the 1980's until today, wrote several papers about the hypothesis. He seemed to only be concerned with chastising misconceptions about the hypothesis, and, as far as I have been able to determine, never actually got around to explaining what, exactly, the hypothesis did say.
Here and here are two such papers. They contain little more than lists of things that the multiregional hypothesis does not predict, but is claimed to predict. While that, of itself, is irritating, what really bothers me is that I can't come up with a reason why MR wouldn't predict most of these things.
For instance, Wolpoff (and co-authors) is insistent that MR does not predict that there would be more genetic and morphological heterogeneity at the "crossroads" of the regional populations than at the peripheries. Yet, as far as I can tell, this should be an unavoidable result of the MR hypothesis as he explains it. He apparently believes that such a pattern of heterogeneity would have been eroded away over the long intervening time periods.
He also claims that MR does not predict that there would be fossils showing hybrid gradients between regional populations. Yet, how could African traits come to dominate non-African populations without either producing hybrids or having Africans migrate out of Africa? He does, however, point to a couple fossils that might be sapiens-Neanderthal intermediates. This gives me the impression that, if hybrid fossils are found, he will claim that MR predicted them; whereas, if they are not, he will argue that MR does not predict them.
He also discusses two interpretations of the MR model that he regards as inaccurate: the "multiple origins" model (in which modern regional populations are descended from archaic populations of the same region) and the "parallel evolution" model (in which traits common to different regional populations evolved separately). My confusion lies in the fact that one or the other, of necessity, must be true, at least to some extent, in order for MR to meaningfully explain anything.
Also, in this paper, he proposed regional continuity in Australasian fossil morphology as evidence of MR, then claims in the first paper cited above the MR does not necessarily predict regional continuity.
In summary, Wolpoff seems to treat his hypothesis the way Intelligent Designists treat theirs. He seems to use a lot of "maybe we would, maybe we wouldn't" reasoning, such that I am left with no insight into what predictions MR actually does make. I'm told by Jon and others that MR predicted admixture between Homo sapiens and other "species" of Homo, but it seems to me that it should have predicted something more specific than that: "Somebody banged a Neanderthal" seems an awfully vague prediction for such a grandiose hypothesis to make.
Edited by Admin, : Fix links.
Edited by Bluejay, : fix link. Thanks, fearandloathing.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

Replies to this message:
 Message 194 by Jon, posted 07-21-2011 7:27 PM Blue Jay has replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 193 of 209 (625163)
07-21-2011 4:38 PM
Reply to: Message 191 by Jon
07-21-2011 3:33 PM


Modern genetic distributions
Hi, Jon.
Jon writes:
Bluejay writes:
You argue that evidence of genetic admixture leads to the rejection of migration as a tenable explanation for anything.
Not really. My argument is that there is no evidence that supports a migration.
You'll forgive me, but this still seems like a semantic quibble. "No evidence that supports" and "reject as tenable" are identical in meaning.
-----
Jon writes:
The migration model is unnecessary to explain modern genetic distributions.
And, we're back to this, I guess. So, I suppose it's time to summarize.
Migration is a much better explanation for the wholesale takeover of one gene pool with genes from another than is passive genetic diffusion through hybridization. The transmission of genes from Africa into Eurasia during the Pleistocene, and the resulting distribution of haplotypes in the modern populations, closely resembles the transmission of genes from Europe to North America during the Colonial Period. Surely this much is undeniable.
From there, we have to decide which is more likely: that archaic Africans migrated out of Africa and gradually conquered the world, or that their genes diffused virtually unmolested throughout all of the world through hybridization while the archaic Africans themselves stayed in Africa.
MR is simply too grandiose a model to seriously explain the distribution of genes in modern human populations. There is no conceivable reason why a model that proposes regional adaptations and extensive hybridization would result in such lopsided dominance by haplotypes from Africa.
I submit that MR has been vindicated as a good explanation for a minority of data in the peripheries of the Pleistocene range of humans, but that it falls spectacularly short in explaining the success of African haplotypes.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

This message is a reply to:
 Message 191 by Jon, posted 07-21-2011 3:33 PM Jon has replied

Replies to this message:
 Message 195 by Jon, posted 07-21-2011 7:43 PM Blue Jay has replied

  
Jon
Inactive Member


Message 194 of 209 (625201)
07-21-2011 7:27 PM
Reply to: Message 192 by Blue Jay
07-21-2011 4:19 PM


Re: Multiregional hypothesis
Here and here are two such papers.
The links don't seem to have come through there; but I would be interested in reading the papers if you have the links.
ABE: It seems the links are in the Peek message but didn't parse right in the final post. Gonna look into the papers and let you know what I think./ABE
Milford H. Wolpoff, one of multiregionalism's strongest proponents from the 1980's until today, wrote several papers about the hypothesis. He seemed to only be concerned with chastising misconceptions about the hypothesis, and, as far as I have been able to determine, never actually got around to explaining what, exactly, the hypothesis did say.
Wolpoff has written two books that I have read, and likely others, regarding human evolution. One of those books, Race and Human Evolution, is concerned almost exclusively with the development and nature of MH; the other is a general text book that gives considerable space to the MH model.
For instance, Wolpoff (and co-authors) is insistent that MR does not predict that there would be more genetic and morphological heterogeneity at the "crossroads" of the regional populations than at the peripheries. Yet, as far as I can tell, this should be an unavoidable result of the MR hypothesis as he explains it.
If you can get a hold of the Race and Human Evolution book, he deals with the issue of 'center and edge', as he calls it, over the span of several pages.
He also claims that MR does not predict that there would be fossils showing hybrid gradients between regional populations.
I've read several pieces of work by Wolpoff where he deals with, argues for, and presents examples of, hybrid forms.
He also discusses two interpretations of the MR model that he regards as inaccurate: the "multiple origins" model (in which modern regional populations are descended from archaic populations of the same region) and the "parallel evolution" model (in which traits common to different regional populations evolved separately). My confusion lies in the fact that one or the other, of necessity, must be true, at least to some extent, in order for MR to meaningfully explain anything.
Without seeing his exact words, I cannot be certain of the accuracy of these claims. This doesn't sound like anything I've read in his work.
Also, in this paper, he proposed regional continuity in Australasian fossil morphology as evidence of MR, then claims in the first paper cited above the MR does not necessarily predict regional continuity.
Again; if you can get the links posted, I can address the issue you've brought up.
"Somebody banged a Neanderthal" seems an awfully vague prediction for such a grandiose hypothesis to make.
And MH doesn't make any prediction that 'somebody banged a Neanderthal'.
Jon
Edited by Jon, : ABE

Love your enemies!

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 Message 192 by Blue Jay, posted 07-21-2011 4:19 PM Blue Jay has replied

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 Message 203 by Blue Jay, posted 07-25-2011 11:18 AM Jon has not replied

  
Jon
Inactive Member


Message 195 of 209 (625202)
07-21-2011 7:43 PM
Reply to: Message 193 by Blue Jay
07-21-2011 4:38 PM


Re: Modern genetic distributions
Migration is a much better explanation for the wholesale takeover of one gene pool with genes from another than is passive genetic diffusion through hybridization.
But we already know that 'passive genetic diffusion' took place, as demonstrated by the evidence presented in this thread. There is, therefore, little reason to suppose a further mechanism when we've already evidence of a perfectly suitable mechanism at work.
that their genes diffused virtually unmolested throughout all of the world through hybridization while the archaic Africans themselves stayed in Africa.
There is nothing in MH about unmolested genes. In fact, quite the contrary; MH would predict that the first wave of gene outflow would show up on the peripheries as being highly 'molested'. However, a continued outflow would eventually lead to the central genetic information overtaking the regional genetic information; each outflow would leave behind less peripheral genetic information in its wake, especially if the outflow involved genes carrying beneficial adaptations.
There is no conceivable reason why a model that proposes regional adaptations and extensive hybridization would result in such lopsided dominance by haplotypes from Africa.
I've mentioned several times in this thread why we would see 'lopsided dominance'. See the paragraph above this one for a brief overview of my position on this.
MR is simply too grandiose a model to seriously explain the distribution of genes in modern human populations.
There's nothing grandiose about it. It's actually quite cozy.
Jon

Love your enemies!

This message is a reply to:
 Message 193 by Blue Jay, posted 07-21-2011 4:38 PM Blue Jay has replied

Replies to this message:
 Message 205 by Blue Jay, posted 07-25-2011 12:02 PM Jon has replied

  
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