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Saturday, July 26, 2014

Neanderthals Didn’t…Didn’t…DID Interbreed with People

Posted by jlwile on May 22, 2010

The original reconstruction of Neanderthal Man (left) and a more realistic reconstruction of a Neanderthal child (right). Both images are in the public domain.

It’s not a really new story, but I was interviewed by an internet radio show about the sequencing of the Neanderthal genome1 and its comparison to present-day people, so I decided I would blog about it as well.

The first thing to discuss is how they sequenced the genome of something that no longer exists. In this case, they used three Neanderthal fossil fragments found in the Vindija cave in Croatia. Fossils (especially those belonging to genus Homo) are rare and very valuable, and this process required the destruction of the fossils, so the three fragments were chosen carefully. They were all fragments that contained very little anatomical information, so anything lost due to the destruction of the fossils was minimal. Based on some pretty good reasoning, it was concluded that the fossil fragments came from three different women, two of which may be relatives. According to scientifically irresponsible dating techniques, these fragments are supposedly around 40 thousand years old.

When they looked at the DNA in the samples they prepared from the bones, they found that between 95 and 99 percent of the DNA came from organisms other than Neanderthals, like bacteria that colonized the fossil. In other words, only 1-5 percent of the DNA found was DNA of interest. How did they get rid of the other 95-99 percent so they could focus on Neanderthal DNA? They used restriction enzymes that tend to cut only bacterial DNA.

So even though this is a remarkable achievement, there are a lot of potential errors in the derived genome sequence. After all, any time the “signal” you are looking at is 20-99 times weaker than the “noise,” it will be hard to determine exactly what the signal is. Keeping in mind these potential errors, what was learned? In short, it was learned that creationists have been right about Neanderthals all along.

As the illustration above shows, when Neanderthal man was first discovered, it was assumed that he was a transitional form between apes and humans. As a result, he was “reconstructed” to be very apelike, despite the fact that the fossils looked very human. Just eight years after the discovery of the first Neanderthal fossil, geologist William King pronounced that Neanderthal man was a completely different species from present-day humans, and he named the species Homo neanderthalensis. The idea that Neanderthal man was a different species from present-day humans has persisted, but creationists have always insisted that Neanderthal man was fully human.

This study, if it holds up, vindicates the creationist position. How does it do that? Well, in the study, the authors compared their Neanderthal genome to the genomes of five present-day humans. The five individuals come from France, China, Papua New Guinea, North Africa, and South Africa. Specifically, they looked at the genome regions that were different among the present-day humans, and they then looked at those regions in the Neanderthal genome to see if the Neanderthal genome was more similar to any of the five current genomes. What they found was that the Neanderthal genome was more similar to the non-Africans than it was to the Africans. This implies that Neanderthals and people interbred.

How do these results imply the interbreeding of Neanderthals and people? Well, the assumption is that if Neanderthals were a distinct population and did not breed with any people, they should be equally unrelated to all present-day humans. However, if some people interbred with Neanderthals, the Neanderthals should be more closely related to the descendants of those people than to the descendants of people with whom no interbreeding took place. Thus, these results indicate that the ancestors of people in Africa did not interbreed with Neanderthals, but the ancestors of the other people represented in the study did interbreed with Neanderthals.

Now, of course, if people and Neanderthals did, indeed, interbreed, then they are clearly from the same species. Thus, this result vindicates what creationists have always claimed. Neanderthals are human beings. They are not some transitional form between ape and human (as was first believed), and they are not some isolated evolutionary dead end (as has been the currently fashionable evolutionary belief). Instead, they are just a specific race of people who went extinct.

The fact that these data belong to the growing list of data which demonstrate the veracity of creationist positions is not, in my mind, the most important aspect of the story. Instead, the important aspect of this story is that it shows how skeptically you should treat the results of any historical science study, including this one.

You see, evolutionists have been trying for years to promote Neanderthals as something less than human. As a result, it was important to portray Neanderthals as not interbreeding with humans. Thus, several studies were performed that “clearly demonstrated” there was no interbreeding between Neanderthals and humans.

For example, in 2004 Dr. Katerina Harvati and her colleagues performed a three-dimensional analysis of several primate skulls, including those of present-day humans and Neanderthals. They concluded that humans and Neanderthals never interbred.2 This led the BBC to report:

The Neanderthals were not close relatives of modern humans and represent a single species quite distinct from our own, scientists say.

In 2008, the mitochondrial DNA of Neanderthal man was sequenced by the same group responsible for the current study. In case you are not aware, there are two places you can find DNA in the eukaryotic cell, which is the kind of cell found in people and animals. You can find it in the nucleus of the cell, but you can also find it in the mitochondria, which are often called the “powerhouses” of the cell. They are given that name because most the process that converts food into energy takes place in the mitochondria.

The DNA that is found in the nucleus is generally just called “DNA,” although it is more properly called “nuclear DNA.” The DNA that is found in the mitochondria is different, and it is called “mitochondrial DNA.” There is significantly less mitochondrial DNA than there is nuclear DNA, so the mitochondrial genome sequence is easier to produce than the nuclear genome sequence. In addition, it is widely thought that only the mother contributes mitochondrial DNA to the child, while both the mother and father contribute nuclear DNA to the child. As a result, the mitochondrial genome is thought to be easier to understand than the nuclear genome.

So what did scientists learn when they compared the Neanderthal mitochondrial genome to the human mitochondrial genome? They determined once again that Neanderthals and humans did not interbreed, at least not enough for Neanderthals to make any lasting contributions to the human mitochondrial genome.3 Indeed, Discover Magazine reported:

Neanderthal DNA Shows They Rarely Interbred With Us Very Different Humans…The team analysed the DNA of 13 genes from the Neanderthal mitochondria and found they were distinctly different to modern humans, suggesting Neanderthals never, or rarely, interbred with early humans.

Now, just two years later, the same group tells us that Neanderthals and humans did, indeed, interbreed enough so that the Neanderthals left a lasting contribution to the present human genome. Why didn’t the mitochondrial DNA show this? According to John Hawks:

The mtDNA of Neandertals is gone because it conferred some disadvantage.

We don’t know what that disadvantage was, but it must have existed, at least according to evolutionary thinking.

So to me, the “take home lesson” of this story is to always be skeptical of new results when it comes to historical science. Up until just two years ago, there were at least two strong lines of evidence that “clearly” showed people and Neanderthals were different species. Today, there is strong evidence that “clearly” shows they are the same species. While I prefer the latter conclusion to the former one, I won’t claim the case is closed. Historical science is fraught with difficulties, and it often takes generations for those difficulties to be uncovered.

REFERENCES

1. Richard E. Green, et al., “A Draft Sequence of the Neandertal Genome,” Science 328:710-722, 2010. Available online with subscription
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2. Harvati K. , Frost S.R. and McNulty K.P., “Neanderthal taxonomy reconsidered: Implications of 3D primate models of intra- and inter-specific differences,” Proceedings of the National Academy of Sciences USA 101:1147-1152, 2004.
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3. Richard E. Green, et al., “A Complete Neandertal Mitochondrial Genome Sequence Determined by High-Throughput Sequencing,” Cell 134:416-426, 2008. available online
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Comments

9 Responses to “Neanderthals Didn’t…Didn’t…DID Interbreed with People”
  1. “According to scientifically irresponsible dating techniques, these fragments are supposedly around 40 thousand years old.”

    Why do you bother reporting this? Why don’t you tell us how old YEC’s think it is?

    “In short, it was learned that creationists have been right about Neanderthals all along.”

    Shocker! I never would have guessed that would be your conclusion.

    “The idea that Neanderthal man was a different species from present-day humans has persisted, but creationists have always insisted that Neanderthal man was fully human.”

    No, it is still debated whether Neandertals should be a separate species or a sub-species of H. sapiens. Why have creationists always insisted that? What is their reasoning?

    “and they are not some isolated evolutionary dead end (as has been the currently fashionable evolutionary belief). Instead, they are just a specific race of people who went extinct.”

    Evolutionary dead end means extinct.

    If anyone wants to actually learn about the Neandertal genome, John Hawks’ blog is the place to go.

  2. jlwile says:

    “Why do you bother reporting this? Why don’t you tell us how old YEC’s think it is?”
    I have to report this, as many people believe in scientifically irresponsible dating techniques. YEC’s think the bones are post-Flood, so they are less than 4,500 years old.

    “Shocker! I never would have guessed that would be your conclusion.”
    Of course not. You don’t care what the data say. You only care what your high priests say. Those of us who actually care about the data, however, will continue to follow it.

    “No, it is still debated whether Neandertals should be a separate species or a sub-species of H. sapiens.”
    Once again, actually read the literature of evolution to avoid demonstrating your ignorance on such matters. Archaeology Info, The Smithsonian, Michgan State Universty, etc., etc. all dogmatically state that Neanderthals are a separate species.

    “Why have creationists always insisted that? What is their reasoning?”
    Once again, if you would bother to LEARN about these things, you wouldn’t have to ask silly questions. Creationists have always insisted this because the Neanderthal fossils are clearly human. All you have to do is look at the fossils without the desire that they be something other than human, and you will see that they are fully human.

    “Evolutionary dead end means extinct.”
    Once again, you just can’t resist displaying your ignorance, can you? This is so much fun! As anyone who has read even a bit of evolutionary biology knows, an evolutionary dead end is a situation in which genetic diversity is lost, precluding the possibility of further adaptation. It doesn’t mean ANYTHING about being extinct. Where in the world do you come up with this nonsense? I doubt that your high priests would say something so ignorant! For example, it is generally thought that self-fertilization in plants is an evolutionary dead end, even though many plants self-fertilize today. In the animal kingdom, sponges are assumed to be an evolutionary dead end. They aren’t extinct, but it is assumed that nothing else has evolved from them.

    Since you don’t even know the basic definitions associated with evolution, it will be hard for anyone to take your advice on resources seriously! Indeed, the more you comment, the less credible you become.

  3. “YEC’s think the bones are post-Flood, so they are less than 4,500 years old.

    On the basis of what data? Can’t you give the younger boundary, standard deviation and confidence level?

    Debate means more than one side. Linking to one side of the debate doesn’t prove anything. And as the first and third are each at least 9 years old, they aren’t the greatest choices. The latest evidence to discuss was released a couple of weeks ago. Here’s just one entry in the debate.

    But the larger point is it really doesn’t matter that much to the bigger picture of human evolution. It is not as fraught with peril as it is for creationists. Homo neaderthalensis or Homo sapiens neaderthalensis. They’re all Homo, and thus human, to evolutionists. The species or sub-species debate is interesting, but not a fight that will change the basic view of human ancestry.

    “All you have to do is look at the fossils without the desire that they be something other than human, and you will see that they are fully human.”

    What DATA are you referring to when you say “look” and “see”? If you can’t show me, then it’s not science.

    I’ll concede on the “evolutionary dead end”. Congrats.

  4. jlwile says:

    “On the basis of what data? Can’t you give the younger boundary, standard deviation and confidence level?”
    The mark of a good scientist is knowing how precisely you can determine something. The bones are found in post-flood strata, so you know they are post flood. Since there is no accurate dating technique for bones or such strata, there is no way of being more precise than that. I know you love to just make up data in order to try to justify your preconceived notions, but I discuss REAL science here, and in REAL science, we don’t make things up.

    “Debate means more than one side.”
    Right. Coming from the person who only links to evolutionists. I link to both, so clearly I know about debate. As usual, you are the one without a clue.

    “And as the first and third are each at least 9 years old, they aren’t the greatest choices.”
    No – they ARE the greatest choices, since I specifically said that the idea of Neanderthals being a separate species has PERSISTED. The older links show it has been around, the newer links shows it is still around. You tried to make the case that the debate has persisted. It has not. The debate is VERY new, and it is not common in evolutionary circles, because most evolutionists dogmatically state that Neanderthals are a separate species.

    The fact that these data demonstrate that Neanderthals are human beings is quite relevant to the creation/evolution debate, as it once again shows that evolutionists were wrong and creationists were right. I know you can’t stand being reminded of that over and over again, but that’s the way it is. The more data that come out, the more this is demonstrated. That’s why it is a great time to be a young-earth creationist.

    “What DATA are you referring to when you say “look” and “see”? If you can’t show me, then it’s not science.”
    Once again, you need to actually EDUCATE yourself on this issue. That way, you wouldn’t look so amazingly ignorant. The characteristics of the bones all fall within the range of modern humans. Thus, there was never any reason to consider them anything other than human. There has even been fossil evidence of a Neanderthal-modern human hybrid. There is evidence of a Neanderthal buried with armor and iron arrowheads. There is strong evidence that Neanderthals cared for their sick, they had normal speech, and they had the dexterity to make modern tools. See what happens when you look at the data? You should try it sometime.

    There is no need to “concede” or “congratulate” me on pointing out yet another one of your many, many errors. I often end up pointing out several errors in just one of your comments. Come on. You couldn’t even be bothered to check your favorite source before making absurdly false statements about the smallpox vaccine. That’s why it is so much fun to read your posts! Very rarely do evolutionists display their scientific ignorance as effectively as you do.

  5. “Since there is no accurate dating technique for bones or such strata, there is no way of being more precise than that.”

    Then why aren’t creationists trying to develop one? And how does a creationist determine where the flood stratum appears in any given geological strata and how old it is?

    The Armoured Neanderthal is by far the most stupid of your creationist links. It reads, in its entirety:

    Around the turn of the century, an anonymous writer in the science journal Nature reported that in the February issue of the Bulletin International of the Academy of Sciences of Cracow, Mr K. Stolyhwo described the discovery of a human skull with classic Neanderthal features. The entire skeleton was in a tomb which also contained iron arrowheads and a suit of chain-mail armour.

    [Italics]This report is no surprise, as Neanderthal bony features have nothing to do with evolutionary ‘ape-man’ beliefs. They are probably just an example of genetic variation among people, more pronounced in the early post-Flood era. Some evolutionists have pointed out that some Neanderthal bony features are found in a percentage of present-day Europeans.[End italics]

    Nature, 77:587 (1908)—as referenced in the Sourcebook series by William Corliss.

    Wow! A 1970′s amateur project citing a 1908 anonymous Nature report citing an earlier issue of the Bulletin International of the Academy of Sciences of Cracow. That’s simply amazing. It’s hard to say, but the second paragraph in italics is probably Corliss. In any case, if you call that DATA, you are crazy.

    “There is strong evidence that Neanderthals cared for their sick, they had normal speech, and they had the dexterity to make modern tools.”

    I’m fine with all these points. Are you trying to say that these things define “human”?

  6. The CEN Technical Journal, which is the fore-runner to Journal of Creation, I found out, lead me to this old earth creationist site, Answers in Creation. I love it! Why didn’t you tell me about them? I also find the US – Australian Answers in Genesis schism to be fascinating. Where can I get the dirt?

  7. jlwile says:

    “Then why aren’t creationists trying to develop one?”
    They most certainly are. In fact, I have discussed one dating method extensively. In addition, there is a new ICR research initiative designed specifically to understand rapid sedimentation more thoroughly. It wouldn’t surprise me if this leads to a good dating method. It is sad that you are so ignorant about basic research going on in origins science.

    “And how does a creationist determine where the flood stratum appears in any given geological strata and how old it is?”
    The word “strata” is the plural form, while the word “stratum” is the singular form. Also, I think you mean something like, “And how does a creationist determine where the flood strata appear in any given geological formation and how old it is?” It is sad that you don’t even understand the science well enough to communicate it properly.

    The position of the flood/post-flood boundary is a basic concept in creation science, showing once again that you know almost nothing about the things upon which you attempt to pontificate. Educate yourself on this issue.

    Thanks for reproducing the article in its entirety. It is a violation of copyright, but since you have no respect for science, it is not surprising that you have no respect for the law. It is also not surprising that you don’t like the evidence. After all, it disagrees with your preconceptions. Those of us who are interested in science recognize it for what it is. Another piece in the huge pile of evidence that led creationists to the correct conclusion, while the evolutionists were (of course) supporting the wrong conclusion. It is instructive to see how you disdain the data that you don’t like.

    “I’m fine with all these points. Are you trying to say that these things define “human”?”
    I am saying that when the bones are all within bounds of the natural variation found in modern humans, and when the behavior is all within bounds of the natural variation found in modern humans, the best conclusion is that Neanderthals were modern humans. As I said before, as long as you don’t WANT them to be anything else, the data clearly say they are fully human. As is usually the case, creationists followed the data, and evolutionists followed what they WANTED to believe. In the end, the creationists have been demonstrated to be correct, which is not surprising. Following the data is always more reliable than following what you WANT to believe. You should try it sometime.

    “Answers in Creation. I love it! Why didn’t you tell me about them?”
    I spend so much time correcting all your mistakes, I don’t have time to expose you to the wealth of creationist views that are out there. I guess it’s too much to ask for you to actually educate yourself for a change. Oh right…I forgot…that kind of education terrifies you. Sorry I brought it up.

    “I also find the US – Australian Answers in Genesis schism to be fascinating. Where can I get the dirt?”
    I have no idea. I don’t pay attention to stuff like that, just as I don’t pay attention to the nasty wars among evolutionists.

  8. With your last link, are you endorsing this:

    “There is no disputing that evolution is a fact, but there are plenty of details of the operation of evolution about which there can be dispute. In this, evolution is far from unique — dispute, disagreement, and conflict are fundamental aspects of science which most non-scientists never see. Everyone else usually ends up seeing the consensus and the things scientists agree on, but behind the scenes scientists debate quite a lot. Even when agreement on something is reached, one answer typically leads to several more questions which people can debate.”

    That’s not a nasty war, however, but how science works, as your more recent post cheerfully admits.

  9. jlwile says:

    Of course I don’t endorse that statement. It is the height of absurdity to state that evolution is a fact. As I have demonstrated, it is at BEST an unconfirmed hypothesis. The link was meant to demonstrate that evolutionists have vicious fights, just like creationists do. As the link says:

    Consistent with the title, much of the Morris’ book is focused on evolutionary biologists themselves — their ideas, their influence, and the sometimes heated debates they have with each other. Actually, “heated” might be an understatement because the vituperative, emotional, and downright nasty things that have been printed in respected science journals sometimes look more like internet flame wars than reasoned, scientific disagreement.

    These kinds of fights do not represent the reasonable disagreements among scientists. Instead, they represent the egos and pettiness of the people involved in the fights.

    Just as I try not to pay attention to the vicious fights that go on in evolutionist circles, I try not to pay attention to the vicious fights that go on in creationist circles. Instead, I try to focus on the data. This, of course, is an idea that is foreign to you, because if you focused on the data, you would have to give up your cherished preconceived notions.

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