Svante Paabo and Neanderthal DNA

Smithsonian.Com has an interesting profile of Svante Paabo. For those of you who are unfamiliar with Svante her is a brief resume:

Paabo landed his first academic post at the University of Munich in 1990. There he expanded his work on the DNA of ancient animals and plants–mammoths, maize, European cave bears. He also resumed his work on ancient human DNA; for example, he was part of the team that managed to sequence some DNA from the “Ice Man,” who was frozen into a glacier in the Tyrolean Alps more than five millennia ago and discovered in 1991.

Recently he has decided to try and sequence the entire Neanderthal genome:

Paabo is also returning to one of his original obsessions. Using a fossil from a site in Croatia, he and his colleagues are trying to derive much longer Neanderthal DNA sequences–not just the DNA that runs the mitochondria, but the DNA that is responsible for building the rest of the body. Their goal is to reconstruct the entire genetic blueprint for making a Neanderthal. It’s a technically daunting task, and Paabo estimates it will take about two years to finish. But being able to compare our genome with that of our evolutionary relatives could highlight key turning points in our evolution.
The ultimate goal of his research, Paabo says, is to identify the genetic changes that made us human. Of course, no historical event can ever be reconstructed completely. But by studying our DNA, scientists eventually will be able to say which genes changed, when they changed, and maybe even why they changed. At that point, we’ll have something we’ve never had before: a scientifically plausible and relatively complete story of our biological origins.

I bring this up because of one of the interesting statements in the article:

More recently, Paabo has taken an even broader view of the genetic changes responsible for our uniquely human traits. For example, mutations in individual genes like FOXP2 may not be the most important force in evolution. An even bigger factor may be changes in the genetic switches that turn on and off many genes at once.[emphasis mine-afarensis] Paabo and his colleagues have been looking at the patterns of gene activity in humans, chimps and other species. As might be expected, the brain has been a particularly active site for recent human evolution. Paabo’s team finds that genes in the human brain have undergone more changes in how they are turned on than similar genes in chimp brains[emphasis mine – afarensis].

Sounds fascinating, especially the connection to evo-devo type research…
Added Later: Kambiz points us to some preliminary results from New Scientist:

The first comparison of human and Neanderthal DNA shows that the two lineages diverged about 400,000 years ago and that Neanderthals may have had more DNA in common with chimps than with modern humans.
There is ongoing debate over whether the Neanderthals were a separate species, Homo neanderthalensis, or a subspecies of Homo sapiens. The first Neanderthals are thought to have emerged about 350,000 years ago, so the new findings from this DNA analysis strongly favour the theory that modern humans and Neanderthals share a common ancestor but are not more closely related than that.

Paabo is also scheduled to speak at the American Society of Human Genetics conference , apparently, so it will be interesting to see what comes out of it. What interests me the most about this is the evo-devo bit highlighted above, rather than the implications for the “Out of Africa vs Multiregional Continuity” debate. I think the fact that we are even thinking about asking evo-devo questions in paleoanthropology says a lot about how far the field has come. I do agree with Anne and Kambiz that there is going to be a lot of hype and overhype before all is said and done…


6 Responses

  1. Regardless of what Paabo finds or doesn’t find in the “Neandertal genome”, the kind of changes that he’s looking for — that which supposedly “made us human” — such genes have probably been around long before there were any Neandertals. What he may find will, IMO, most likely turn out to be ambiguous at best, whatever interpretation Paabo puts on it.
    Anne Gilbert

  2. I agree, if only a homo erectus could be compared genetically to an afarensis …

  3. I’m not sure I agree. Comparing the Neanderthal genome with the human genome as well as drafts of the chimp and macaque genomes should give us some interesting clues about selection events in the human lineage. I don’t think we will have a “relatively complete story of our biological origins” anytime soon, though – at least not in the sense Paabo meant.

  4. “Neanderthals may have had more DNA in common with chimps than with modern humans” is bogus. This claim seems to be a mistake of the journalist.

  5. I first read of Paabo’s research 10 years ago in the Orlando Sentinel newspaper in an article titled, “Rest assured: You’re not related to Neanderthals,” dated July 11, 1997. I don’t see any significant changes since then.
    First, if Paabo’s research shows that modern humans did not evolve from the ancient, primitive species, it thus shows that human evolution is a myth, and creation is more plausible.
    If the following is true, that “the researchers found an average of 27 differences between modern and Neanderthal DNA — far more than the typical variation of eight among modern humans,” then the answer may be found in the Bible. Let me suggest that since the Noah and the flood, humans have a typical variation of eight DNA. Isn’t it interesting that only eight people survived the great flood. Except for Noah’s righteous family of eight that was spared by God, God destroyed the unrighteous and their “seed” (DNA) was wiped from the face of the earth.
    I also find it interesting that since the flood, modern man has a CONSTANT eight differences in DNA, whereas pre-flood man had a VARIABLE number of differences in DNA, averaging 27. The Bible has the answer.
    The Bible is the answer.
    Thomas Rhoden
    February 14, 2007

  6. There are a number of statements in your comment that are just wrong. For example, Paabo found that the lineage leading to Neanderthals and the lineage leading to humans split somewhere between 400,000 and 700,000 years ago. Phrased differently, Paabo’s research shows that Neanderthals and Homo sapiens are sisters (technically, sister taxa) not parent and offspring. Reading the report in the science journals makes it clear that there are more differences than 27. The rest of your comments concerning the number of genetic differences between modern humans is completely wrong as well.

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