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Member (Idle past 5291 days) Posts: 766 From: Newcastle, Australia Joined: |
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Author | Topic: Comparisons of Neandertal mtDNA with modern humans and modern chimpanzees | |||||||||||||||||||||||
coffee_addict Member (Idle past 508 days) Posts: 3645 From: Indianapolis, IN Joined: |
redwolf writes: Basically, somebody who wanted to go on believing that modern man had evolved would have to come up with some new hominid, closer to us (than the neanderthal) in both time and morphology, to claim as a human ancestor. I don't mean to whip out logic on you, but what you've done is commit a fallacy called appeal to ignorance. You are basically saying that just because we haven't found a homonid close enough to modern man that such a homonid doesn't exist. Drawing a conclusion from an incomplete record is as ignorant as anyone can get. Edited-wrong info. [This message has been edited Lam, 05-03-2004] The Laminator
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Sylas Member (Idle past 5291 days) Posts: 766 From: Newcastle, Australia Joined: |
Lam writes: You are basically saying that just because we haven't found a homonid close enough to modern man that such a homonid doesn't exist. Drawing a conclusion from an incomplete record is as ignorant as anyone can get. More to the point, we do have the remains of such hominids; many of them. Redwolf even mentions some, but his discussion is flawed by various other errors. I'm sure we'll discuss this some more as the thread continues.
Neanderthal works and remains have only been found in Europe, not all over the map. Get your facts straight! Neadertal remains have been found more a bit more widely than this. As well as finds in Europe, there are finds in Syria, Israel, Uzbekistan, Morocco and Iraq. Some of these fossils are described at Homo neanderthalensis, at Stephen Heslip's pages at Michigan State University, for a course on Hominid Fossils. Cheers -- Sylas
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coffee_addict Member (Idle past 508 days) Posts: 3645 From: Indianapolis, IN Joined: |
Sylas writes: Neadertal remains have been found more a bit more widely than this. As well as finds in Europe, there are finds in Syria, Israel, Uzbekistan, Morocco and Iraq. Some of these fossils are described at Homo neanderthalensis, at Stephen Heslip's pages at Michigan State University, for a course on Hominid Fossils. Really now. My bad. I've always thought they were unique to Europe. Oh well. What about Africa? Has there been findings of them in Africa? The Laminator
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Sylas Member (Idle past 5291 days) Posts: 766 From: Newcastle, Australia Joined: |
Lam writes: What about Africa? Has there been findings of them in Africa? Not that I know of. The find at Jebel Irhoud, which is the basis for my listing Morroco in the previous post, would be Africa. It is just across from Gibraltar, but I think the identification with Neandertal may be contentious. The Neandertal range is given by Francis Steen as follows:{Image is a link to source; uses current browser window} The source for this map is the same that redwolf used in Message 9 for skull pictures. Seems to be comprehensive and high quality, with copious references to diverse views within the scientific community. Thanks for the reference. Cheers -- Sylas
Edit change. The map was previously taken from Neanderthal Sites (by D.S. McDonald). It is now taken from a different source, used by redwolf, and is properly linked. [This message has been edited Sylas, 05-03-2004]
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JonF Member (Idle past 199 days) Posts: 6174 Joined: |
For anybody who hasn't really followed the argument, the question as to whether the neanderthal dna findings would justify a claim that the neanderthal was "about halfway between us and chimpanzees" is not crucial to the case I would try to make. That's just a figure of speech. ROFLMAO! To anybody who has followed the argument, the claim and case you made was that neandertals were literally about halfway between humans and chimpanzees and neandertals were not our ancestors (see http://EvC Forum: Aquatic Ape theory? -->EvC Forum: Aquatic Ape theory?); nothing more and nothing less. It wasn't a figure of speech, you argued for its literal truth, and you were flat-out wrong.
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redwolf Member (Idle past 5822 days) Posts: 185 From: alexandria va usa Joined: |
Nonetheless, it seems clear enough that that does not save the picture for purposes of evolution. When they used to draw homonid progressions leading up to modern man (which you say you don't like), the final two things before modern man were homo erectus, and neanderthal, it seeming obvious to scientists that the neanderthal was the closest (morphologically) hominid to us, and then erectus, and then the guys further down and back. Depending on whose picture of archaic homo sapiens you use, you are either still trying to claim that modern man descended from something essentially identical to the neanderthal, which has been coercively disproven by the combination of the dna studies and Shreeve's study, or you are trying to claim that something marginally different from us descended from homo erectus, which is a great deal more apelike than the neanderthal, which nobody should believe in light of the recent findings. Moreover, there aren't "many" of these. The one skull in terribly bad shape is said to be the most complete, and they appear to be rare. Too rare for modern man to be descended from them.
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Sylas Member (Idle past 5291 days) Posts: 766 From: Newcastle, Australia Joined: |
redwolf writes: Sylas writes: The first phrase is true, and the second is false. The findings do not give any indication that interbreeding was precluded. They only indicate that there was no detectable genetic contribution made. These are different claims. The paper indicates that the difference between Humans and Neandertals is less than the difference between Western and Eastern varieties of the common chimpanzees... and they are completely interfertile, and yet also with distinct gene pools because interbreeding does not usually occur. I posted this the other day and you supposedly read it. Here it is again: http://www.findarticles.com/..._86/70362289/p2/article.jhtml
Again, James Shreeve made an overwhelming case for the impossibility of crossbreeding between neanderthals and modern man and this paper is generally acepted as definitive on the subject at this point. The dna findings basically just confirmed Shreeve's analysis. I read it better than you, apparently! The very next paragraph after the bit redwolf gives in red reads as follows (my emphasis in bold).
How, then, could the Lagar Velho child be of mixed Neanderthal--early modern human background? Even newer biological evidence suggests that the Germans may have been wrong in their conclusion about DNA differences, Zilhao writes in a recent issue of Archaeology magazine. Shortly after the publication of the German scientists' DNA analysis, the results of a separate study of chimpanzee DNA were released. Did you read that bit? Yes, I read your link, and the other ones you gave also. You can get all kinds of diverse opinions on this. I have no problem if it turns out that Shreeve disagrees with me, and indeed no problem if there is new evidence that leads me to change my mind. Interbreeding, and interfertility, are still open questions, and the data continues to be collected and examined and tested in various new ways. Shreeve is explicit about this in the end of the article you have quoted:
In any case, archaeologists keep digging. Future discoveries may yet reveal whether the early modern humans saw the Neanderthals as people like themselves and mingled with them to produce hybrids like the Lagar Velho child, or whether they kept their genetic distance. Here are a couple more points you should note.
In the meantime, my extract quoted above remains unambiguously true; it is a straight description of the actual data which we need to consider. The actual empirical data indicates that the genetic difference between Neandertals and Humans was less than the difference between interfertile subspecies of the common chimpanzee, and much less than the difference between common chimpanzee and bonobos, which are also interfertile. Indeed Shreeve mentions this himself, in your first linked article! Shreeve's speculation (not analysis) is an attempt to reconcile the evidence I have cited on comparisons with chimpanzee diversity (which indicated that Neadertals probably were interfertile with Homo sapiens) and the genetic evidence of Krings et al (which suggests that Neadertals did not contribute to the modern gene pool). And even then, Shreeve acknowledges that there is room for future evidence to contribute further understanding. I agree with him on all these three points; and I think his proposed solution, of lack of mate recognition, is very plausible. I think you need to read that article again, and more carefully. Cheers -- Sylas
PS. You would be better to remove "?term=" from your link to the first Shreeve article. I have removed it from the URL in the quoted extract from your post. Link construction code here fails to parse the "=" as part of the link. You can also work around the problem by making the links explicitly, rather than leaving a bare URL in your post.
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jar Member (Idle past 425 days) Posts: 34026 From: Texas!! Joined: |
however there have been finds all across the northern and eastern shores of the Med. That would lead me to belive that it is certainly possible if not even likely that we will oneday find examples of Neanderthal habitation along the southern shore of the Med as well.
Aslan is not a Tame Lion
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RAZD Member (Idle past 1436 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Another possibility is that the interbred offspring were infertile - mules. This would allow a child or any individual specimen to have mixed DNA, but still no neander DNA in human genome.
Personally I have wondered if the temporal overlap between sapiens and neander is the root of the troll and ogre myths. This would shed some light on group interactions. I suppose one could do a search on the location origins of the myths and see if they match the population data to get some inference of validity, but it would be extremely difficult to make more than a hypothetical case. we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}
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redwolf Member (Idle past 5822 days) Posts: 185 From: alexandria va usa Joined: |
>Did you read that bit?
No. I stopped reading at the point of the German scientists claiming that interbreeding would not be possible. I was trying to look at several such articles and was in too much of a hurry. Nonetheless, the one or two skeletons which anybody is making any such claims for could be anything and do not come close to answering the mail for the problem which Shreeve notes, i.e. that you had the two groups living close to eachother for very long periods of time, and that if interbreeding was possible, there should be crossbreed skeletons all over the place; they should be very easy to find. It's also interesting that the one skeleton anybody is claiming as a crossbreed skeleton is that of a child; that may be as long as such crossbreeds ever lived.
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redwolf Member (Idle past 5822 days) Posts: 185 From: alexandria va usa Joined: |
Are members allowed to post on the 'proposed new topic' area?
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AdminSylas Inactive Member |
Members can post new topics in Proposed New Topics, but they can't add posts to a thread. Moderators will approve new topics into the appropriate forum, after which all members may join in.
For more details, see Message 1 and following, and Message 53. And discussion or comments is being actively solicited, and is very welcome. Please give it in those threads, not in followup to this thread. AdminSylas
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RAZD Member (Idle past 1436 days) Posts: 20714 From: the other end of the sidewalk Joined: |
I have extended the photo gallery from my previous message:
A Cro magnon skull specimen has been added at the front, while Homo habilis and Homo rudolfensis have been added at the end. I have also shown the "calibration" lines that I used to size the pictures in order to take out variation that could be from individual specimens and to show relative proportions. This is in answer to the claim by redwolf\ted that there is a major discontinuity in the family tree (Note that his "archaic" Homo sapiens is now considered Homo heidelbergensis and is shown as such here). Enjoy. ps - ted: the New Proposed Topics is the place to start new topics, see http://EvC Forum: HOW TO START A NEW TOPIC (as of 4/13/04) [This message has been edited RAZD, 05-03-2004] we are limited in our ability to understand by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}
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sfs Member (Idle past 2564 days) Posts: 464 From: Cambridge, MA USA Joined: |
No; that was the HVRII. There was no difference given for the HVRI, which was the subject of my second plot.
Sorry, I wasn't paying attention. (Maybe I shouldn't have had a Buffy episode on in another window.)
I'm collecting a set of references for this. Can you give a cite where I could track down more on these, please? Does mtDNA diversity give any different result to nuclear DNA diversity?
Yu N, Jensen-Seaman MI, Chemnick L, Kidd JR, Deinard AS, Ryder O, Kidd KK, Li WH. Low nucleotide diversity in chimpanzees and bonobos.Genetics. 2003 Aug;164(4):1511-8. There's also data from the chimp genome effort on western and central chimps -- it's the actual source I was using, but it hasn't been published yet. It will be available Real Soon Now.
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Sylas Member (Idle past 5291 days) Posts: 766 From: Newcastle, Australia Joined: |
sfs writes: Sorry, I wasn't paying attention. (Maybe I shouldn't have had a Buffy episode on in another window.) Sheesh -- get your priorities right. You should always have a Buffy episode on in another window. I have another question, which you or others may be able to help me with. In previous posts, I have assumed that the chimpanzee subspecies are interfertile. However, I can't confirm this; and on checking I could be wrong. It seems that the close similarity indicates to most researchers that hybrids are extremely likely, and if I recall correctly, conservation groups advocate that chimpanzees in captivity should be maintained in their distinct subspecies in order to prevent cross breeding and loss of diversity. Is anyone aware of whether or not there are any confirmed instances of fertile hybrid offspring from any of the chimpanzee subspecies? Are there any populations of distinct subspecies which are in contact with each other, so that interactions across subspecies lines would be possible? Cheers -- Sylas
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