Creationist Arguments: Neandertal mtDNA

Initial creationist responses to this research were cautious. A common, and legitimate, response is to point out that the result has not yet been replicated and may be in error. While possible, this does not seem like a high probability at the moment. The researchers took impressive precautions, and all the bases of the Neandertal mtDNA sequence were verified in at least two separate extractions.

Creationist Marvin Lubenow has published a detailed critique of the mtDNA study (Lubenow 1998). The first part of his paper discusses evidence from the fossil record for continuity between Neandertals and modern humans. Not being familiar with this evidence, I will discuss the section of his paper which deals with the mtDNA evidence. After summarizing the Cell paper, Lubenow then lists his objections.

1. Lubenow objects to the comparison of the average distance between all modern humans (8.0) with the average distance between modern humans and the Neandertal (27.2), arguing that it is invalid to compare an average difference of many humans with a value from a single individual. He states "Thus, there is no Neandertal 'average', ...". This is true, but no one has ever claimed that 27 was an average value for Neandertals. It is only claimed that 27 was the average distance from that specific Neandertal to all modern humans, and that claim is quite correct.

It is true that comparing an "average" human value of 8 with the Neandertal value of 27 does not give us the full picture. Ideally, we would like to know the distribution of equivalent values for humans (e.g. what is the maximum "average difference" among modern humans). Although that figure is not known, it is clear that it must be far less than the average distance of the Neandertal from humans. Certainly, it is more meaningful to compare the average human value with the Neandertal value than it would be to take the difference of the two most atypical individuals we can find and then compare that with the minimum difference between a Neandertal and many humans, as Lubenow does.

Lubenow points out that some analogies by popular science writers have been misleading. For example, a Discover article by Robert Kunzig (1997) visualizes the human distribution as a crowd of modern humans huddled around a campfire, with no one more than 8 yards from the centre, while the Neandertal is 27 yards away from the center. Ignoring for now the fact that mtDNA distributions are not easily visualized in terms of normal geometry, and assuming that the distance from the campfire is meant to be proportional to the average distance from other humans, Kunzig's analogy is inaccurate because some humans have an average distance of more than 8, and at least 12, from other humans. Unfortunately Lubenow's suggested correction of this analogy is even worse. He has some humans only 1 yard from the campfire (invalid, because no human can have an average distance of 1 from other humans), while he would put a few humans at 24 meters from the campfire. This is inaccurate because no human is an average of 24 away from other humans. A better analogy of the value of 24 would be two humans who are both 12 yards away from the campfire and on opposite sides of it. This analogy then shows the Neandertal well outside the human range, which accurately reflects the mtDNA data.

Problem of Species distance.
Problem of evolutionary time and distance
Molecular clock problems
using mtDNA to determine relationships
Lubenow suggests that copying errors in the PCR (polymerase chain reaction) process could cause the Neandertal sequence to appear to be more distant from modern humans than it really is. He cites John Marcus, who suggests that damage to the original mtDNA could have caused consistent misamplification of some bases. Firstly, it is hard to see how damage could have affected the same bases in the same way in different DNA molecules (every base position was independently extracted at least two times). Secondly, almost all the positions in which the Neandertal differed from the human reference sequence were positions in which some modern humans differ from one another (Krings et. al., p.24). As Stoneking points out, "if most of the Neandertal differences had turned out to be in non-polymorphic positions, we would be worried that we were detecting post-mortem DNA damage and not authentic substitutions", but such was not the case.
Philosophical biases

Marr makes the amazing statement that:

"That theory [Out of Africa] predicts that Neandertals were a separate
species (Creationists have been saying that for a long time!!!)."

I don't know which creationists Marr reads, but the creationist literature with which I am familiar is overwhelmingly of the opinion that Neandertals were merely modern humans.

By contrast, some old-earth creationists such as Hugh Ross have enthusiastically embraced the mtDNA results, claiming that they confirm that Neandertals were a separate species. While the mtDNA results did strengthen the already generally held belief that Neandertals were not ancestral to modern humans, they certainly did not show, as Ross claims, that they are unrelated to humans.

Since few people were expecting Neandertal DNA to be extracted, I am not aware that any creationist ever made a prediction as to whether their mtDNA would be similar to modern humans or not. But from reading creationist literature about Neandertals, it seems virtually certain that they would have predicted their mtDNA to fall in the normal human range. After all, almost all creationists consider Neandertals to be post-Flood descendants of Noah (like all modern humans) who suffered from diseases or severe environmental conditions. If the new findings are correct, as seems probable, it is going to be extremely difficult for creationists to reconcile them with this scenario, or any other young-earth scenario, without assuming unreasonably high mutation rates.

Creationist Responses

Recovery of Neandertal mtDNA: An Evaluation, by Marvin Lubenow

A Shrinking date for Eve, by Carl Wieland

Will the real Neandertal please stand up?, by Robert Harsh

Neanderthal DNA Soup, by Do-While Jones

Descent of man theory: disproved by molecular biology, by Richard Deem

Neanderthal DNA, by David Plaisted

Were the Neanderthals Related to Modern Humans?, by Trevor Major

***Mother Eve in dispute with ape-man, by Nancy Darrall

Latest theories regarding the Neandertal, by Jeffrey Marr

Lubenow M.L. (1998): Recovery of Neandertal mtDNA: an evaluation. Creation Ex Nihilo Technical Journal, 12:87-97.

Neandertal Takes a One-Eighty, by Hugh Ross

References

Lubenow M.L. (1998): Recovery of Neandertal mtDNA: an evaluation. Creation Ex Nihilo Technical Journal, 12:87-97.

Kunzig R. (1997): The face of an ancestral child. Discover, 18, 88-101.

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This page is part of the Fossil Hominids FAQ at the talk.origins Archive.