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Thread: Neanderthal Genome Sequencing Yields Surprising Results And Opens A New Door To Futur

  1. #1

    Neanderthal Genome Sequencing Yields Surprising Results And Opens A New Door To Futur

    http://www.sciencedaily.com/releases...1116083223.htm

    Date: November 16, 2006

    Neanderthal Genome Sequencing Yields Surprising Results And Opens A New Door To Future Studies

    The veil of mystery surrounding our extinct hominid cousins, the Neanderthals, has been at least partially lifted to reveal surprising results. Scientists with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the Joint Genome Institute (JGI) have sequenced genomic DNA from fossilized Neanderthal bones. Their results show that the genomes of modern humans and Neanderthals are at least 99.5-percent identical, but despite this genetic similarity, and despite the two species having cohabitated the same geographic region for thousands of years, there is no evidence of any significant crossbreeding between the two. Based on these early results, Homo sapiens and Homo neanderthalensis last shared a common ancestor approximately 700,000 years ago.
    This is the most fascinating part:

    Comparing Neanderthal to human and chimpanzee genomes showed that at multiple locations the Neanderthal DNA sequences matched chimpanzee DNA but not human.
    Neanderthals aren't related to humans but it looks like they were an extinct member of the great ape family. I wonder if bigfoot/yeti are the last of the neanderthals.
    Last edited by antiquity; 11-17-2006 at 10:19 PM.

  2. #2
    Senior Member rdf's Avatar
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    Quote Originally Posted by antiquity
    http://www.sciencedaily.com/releases...1116083223.htm



    This is the most fascinating part:



    Neanderthals aren't related to humans but it looks like they were an extinct member of the great ape family. I wonder if bigfoot/yeti are the last of the neanderthals.
    ----

    I think neandertal man and modern man share a common ancestor. I can't remember which, homo erectus, or homo ergaster.

    But I think neandertal were just the guys who left africa first, maybe almost a million years past, and got caught in the colder climates during ice ages...while the rest of the homo erectus population stayed in africa, or moved on to china, becoming peking man. Homo erectus went all over the world, I think.

    The homo erectus or ergaster that stayed in Africa developed into homo sapien due to healthy living from warm climates, and homo sapien are anatomically correct modern humans.

    But basically, what I've read over the past few years (it has really interested me, that's why I've read so much on neandertal man) tells me that neandertal are our distant cousins, and we all had the same ancestor...I don't know about the chimpanzee connection, but we must share a common ancestor with chimps going back millions of years, too.

    But I could be wrong, seneca, as has been proven to me many times in the past
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  3. #3
    antiquity, thanks for posting this. This is an analysis of mitochondrial DNA, which is passed only by Neanderthal women to their offsprings. There were three interesting discovery:

    1. The most interesting is the absence of homo sapien mitchondrial DNA. This finding suggests that Neanderthals have not been mating with homo sapien females although it doesn't rule out the possibiity of homo sapien men mating with neanderthal females. The answer to the question of homo sapien men mating with neanderthal females must await the sequencing of nuclear DNA, particularly the Y-chromosome.

    2. The presence of some chimpanzee DNA in the Neanderthal mitochondrial genes suggests that some ancestor of Neanderthal mated with female chimpanzees or an female ancestor of chimpanzees.

    3. The estimate of the separation of the two species was dated to over 400,000 years ago. That is a long time. That is a long time for species (i.e. the ancestors of homo sapiens) to be co-existing and not interbreed at all. There must have been some barrier. I wonder what that barrier is. As pointed out in a Discover Magazine magazine in 1995 (Source:
    The Neanderthal peace.(Neanderthals and modern man somehow coexisted for 50,000 years without mating or exterminating each other)
    From: Discover | Date: September 1, 1995 | Author: Shreeve, James
    Discover

    Fossils from Israel suggest that Neanderthal and modern-looking humans coexisted for up to 50,000 with no morphological convergence, which means they never mated. One explanation could be that the mate-recognition systems were so different that the idea of inter-species mating never came up.
    Note that the Neanderthal has a larger cranial cavity than homo sapiens, suggesting that they did not lack for brain size and presumably intelligence.

    Wise.
    Last edited by Wise Young; 11-17-2006 at 10:55 PM.

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    Senior Member rdf's Avatar
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    Somewhere in my readings on this subject, I read where they've found a skeleton of a child who had both neandertal and homo-sapien attributes...so homo-sapien man may have mated with female neandertal, either during war (slave rape?), or curiosity...or if lone homo-sapiens somehow became disconnected from their band, and lived with neandertal. Would neandertal allow this? Just something else I'd love to know.

    I suppose we'll find out for sure one of these days if homo sapien man mated with the females of neandertal.

    It's just fascinating to me. Neandertal understood death/afterlife to the extent that they usually buried their dead in shallow graves, and left ornaments, weapons, etc., and many believe that had associated "rituals" at the burial site. There have also been found neandertals with healed broken bones, meaning they cared for their injured.

    And once homo sapien arrived in neandertal lands, neandertal's tools improved, as did their rudimentary art, weapons and ornaments, etc. So they could learn well, and as you mention Wise, they had big enough brains to do whatever homo sapien could do...bigger than our own.

    I'm not sure if they could communicate in any way but rudimentary, but I think they had the prerequisite anatomy for advanced speech. There are so many questions I'd love to find the answers to...if I hadn't have been injured and had another chance, I'd be either a biblical archaeologist, or a forensic anthropologist.

    I think neandertal were doomed because they spent so much of their time fighting the elements, and fighting to just survive; maybe they didn't have the free time needed for philosophical wonderings and wanderings, and spiritual consideration and advancement of ideas. These are the kinds of thoughs that led to god(s) and organized religions, and civilization itself.

    When modern man came along, they just couldn't handle it. I just think that although they were excellent hunters, they couldn't compete with the smarter species, homo-sapien.
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  5. #5
    Quote Originally Posted by Wise Young
    antiquity, thanks for posting this. This is an analysis of mitochondrial DNA, which is passed only by Neanderthal women to their offsprings. There were three interesting discovery:

    1. The most interesting is the absence of homo sapien mitchondrial DNA. This finding suggests that Neanderthals have not been mating with homo sapien females although it doesn't rule out the possibiity of homo sapien men mating with neanderthal females. The answer to the question of homo sapien men mating with neanderthal females must await the sequencing of nuclear DNA, particularly the Y-chromosome.

    2. The presence of some chimpanzee DNA in the Neanderthal mitochondrial genes suggests that some ancestor of Neanderthal mated with female chimpanzees or an female ancestor of chimpanzees.

    3. The estimate of the separation of the two species was dated to over 400,000 years ago. That is a long time. That is a long time for species (i.e. the ancestors of homo sapiens) to be co-existing and not interbreed at all. There must have been some barrier. I wonder what that barrier is. As pointed out in a Discover Magazine magazine in 1995 (Source:


    Note that the Neanderthal has a larger cranial cavity than homo sapiens, suggesting that they did not lack for brain size and presumably intelligence.

    Wise.
    I agree with the Discover magazine article. Aesthetically, I think they were so different looking (neanderthals weren't human afterall) that the idea of interbreeding never occured to them. Different animal species live side by side too without ever interbreeding so I don't find it particulary unfathomable.

  6. #6
    The more that I think about it, the more I believe that the conclusion that there was no interbreeding between Neanderthal and Homo Sapiens is simply not well justified by mitchondrial DNA data for the following reasons.

    Mitochondrial genes are passed on by females only. Only if a sapien female were to mate with a neanderthal male would any sapien mitochondrial genes pass onto the offsprings. Only female offsprings of that union would carry the mitochondrial genes of the sapien female. Only neanderthals that are direct descendants of the original sapien female would carry sapien mitochondrial genes.

    Suppose that the scenario depicted by Jean M. Auel in the Clan of the Cave Bear had occurred and a female homo sapien were to be abducted or stranded in a clan of neanderthals. As illustrated in the following figure, propagation of mitochondrial genes is relatively inefficient. A male would not propagate any mitochondrial genes. If a group of male sapiens were to capture a group of Neanderthal females and mated with all of them, none of the offsprings would possess sapien mitochondrial genes.

    Mitochondrial genes are relatively vulnerable to extinction if a sapien female were less attractive to neanderthal males or less fertile than a neanderthal female. Over several generations, this could easily lead to extinction of the sapien mitochondrial genes in the clan. On the other hand, males possessing sapien genes will continue to pass those genes onto offsprings.

    So, the failure to find sapien mitochondrial genes in a single neanderthal specimen does not necessarily mean that there was no interbreeding between homo sapiens and homo neanderthalis. It would not rule out the possibility of a male sapien mating with a female neanderthal. Likewise, it would not rule out the possibility of a female homo sapien mating with a neanderthal male but failed to produce female offsprings or produced female offsprings that were less attractive to neanderthal males or less fertile.

    Please note that the above would be also true if a neanderthal female were to stranded or abducted in a clan of homo sapiens. Only direct descendents would possess her mitochondrial genes and only if at least one female in each generation had a female offspring. Thus, mitochondrial genes are not a particularly good marker of interbreeding of two species. Before the authors can conclude that there is no interbreeding between homo sapiens and neanderthals, they would have to conduct additional studies of more neanderthal specimens.

    There is one other flaw in the logic. Presumably, the authors used morphological criteria to identify the neanderthal remains from which they did the analysis. This may select for a member of a neanderthal clan whose ancestors did not breed with homo sapiens. Earlier studies had reported a lack of morphological convergence between the skeletal features of Neanderthals and Cro Magnon men (existing concurrently with Neanderthals). But this simply means that one or the other skeletal form is dominant.

    I predict that sequencing of the nuclear genes of the Neanderthal will show more evidence of cross-breeding between homo sapiens and neanderthals than concluded from the analysis of mitochondrial genes

    Wise.
    Last edited by Wise Young; 11-18-2006 at 05:06 AM.

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    Senior Member rdf's Avatar
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    Modern Humans, Neanderthals May Have Interbred


    MONDAY, Oct. 30 (HealthDay News) --

    There may be a little Neanderthal in all of us.

    That's the conclusion of anthropologists who have re-examined 30,000-year-old fossilized bones from a Romanian cave -- bones that languished in a drawer since the 1950s.

    According to the researchers, these early Homo sapien bones show anatomical features that could only have arisen if the adult female in question had Neanderthal ancestors as part of her lineage.

    The findings may answer nagging questions: Did modern humans and Neanderthals interbreed on a significant scale? And were the Neanderthals exterminated about 28,000 years ago -- as some anthropologists contend -- or did they gradually assimilate into the gene pool of people living today?

    "From my perspective, the replacement vs. continuity debate that raged through the 1990s is now dead," said the study's American co-author, Erik Trinkaus, a professor of anthropology at Washington University in St. Louis.

    Trinkaus comes down firmly on the side of the assimilation theory.

    "To me, what happened is that the Neanderthals were [genetically] absorbed into and overwhelmed by modern humans coming into Europe from Africa, and they disappeared through this absorption," Trinkaus said. His team published its findings in this week's issue of the Proceedings of the National Academies of Sciences.


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    rdf, I am surprised that the Neanderthal mitochondrial DNA analysis paper concluded on the basis of mitochondrial DNA that there was little interbreeding between Neanderthals and Homo Sapiens. That is what makes the nuclear protein analysis very important. At stake is whether or not there has been a race of humans who co-existed with homo sapiens but never interbred with us. It seems unlikely but that is what is great about science. The most unlikely things can happen.

    Wise.

    Quote Originally Posted by rdf
    Modern Humans, Neanderthals May Have Interbred


    MONDAY, Oct. 30 (HealthDay News) --

    There may be a little Neanderthal in all of us.

    That's the conclusion of anthropologists who have re-examined 30,000-year-old fossilized bones from a Romanian cave -- bones that languished in a drawer since the 1950s.

    According to the researchers, these early Homo sapien bones show anatomical features that could only have arisen if the adult female in question had Neanderthal ancestors as part of her lineage.

    The findings may answer nagging questions: Did modern humans and Neanderthals interbreed on a significant scale? And were the Neanderthals exterminated about 28,000 years ago -- as some anthropologists contend -- or did they gradually assimilate into the gene pool of people living today?

    "From my perspective, the replacement vs. continuity debate that raged through the 1990s is now dead," said the study's American co-author, Erik Trinkaus, a professor of anthropology at Washington University in St. Louis.

    Trinkaus comes down firmly on the side of the assimilation theory.

    "To me, what happened is that the Neanderthals were [genetically] absorbed into and overwhelmed by modern humans coming into Europe from Africa, and they disappeared through this absorption," Trinkaus said. His team published its findings in this week's issue of the Proceedings of the National Academies of Sciences.


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    I liked the book better than the movie.http://www.actionmax.tv/index.php?page=previews&id=1

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