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Thursday, December 18, 2008

The Neanderthal Project

The NYT recently reported that DNA sequencing of the Wooly Mammoth genome is now possible, using two fossilized hair samples, recovered from mammoths that died 20,000 and 60,000 years ago. NYT reports that scientists are now discussing how to modify DNA in the mammoth's closest living relative, the African elephant, so that it resembles the wooly mammoth. The elephant genome, according to Stephan C. Schuster and Webb Miller at Penn State, will need to be modified at about 400,000 places to make it resemble its hairer cousin. As the thinking goes, once modified at these locations, the elephant genome will be, effectively, a woolly mammoth genome, which can then be brought to term in a female elephant. The elephant would have a wooly mammoth. This clever technique makes moot the prior thinking that a mammoth genome would need to be synthesized in the laboratory. No need to do this (and we can't anyway), because we've got the elephant's cell, and with the mapping of the mammoths DNA, we can translate the one to the other.

So far so good, but there's (or was) a hitch: 400,000 changes are a lot of changes, and the process will likely be arduous to the point of not feasible. Enter the "454 machines", which automate a revolutionary new sequencing technique, that, in effect, let biologists do the genomic modifications in batches. According to George Church, genome technologist at Harvard Medical School, about 50,000 "corrective DNA sequences" can be injected into the cell at one time. In this case, with only a few iterations the machines could inject the entire set of necessary modifications, making the science-fiction like scenario a reality.

The cost estimate for the wooly mammoth project is about $10,000,000, which, while not chump change, is a figure that gaurantees that someone with deep pockets and an interest in our archaelogical past will see things through.

As if this isn't zany enough, there are efforts underway to regenerate the Neanderthals, a hominid race closely related to homo sapiens (us) that lived approximately 200,000 to 45,000 years ago, inhabiting Europe, and possibly coexisting with our direct Cro Magnon descendents. No one knows, conclusively, why the athletic, possibly dim-witted, Neanderthals died out those thousands of years ago. We don't know whether they could talk, or to what extent they created a culture similar to early humans (there is evidence that they drew paintings, suggesting an ability to communicate abstractly). What is certain is that, if the sequencing techniques work on the wooly mammoths, there will be no scientific reason that they can't likewise be applied to generating Neanderthals, if (or when) the extinct species' full genome is recovered.

Work on The Neanderthal Project is well-underway. Svante Paabo of the Max Planck Institute for Evolutionary Anthropology, for instance, has been diligently reconstructing the DNA of Neanderthals using bone fragments discovered in Eastern Europe. With the help of the new "454" sequencing machines, he -- along with a similar project at Lawrence Berkely National Laboratory -- expects to get a complete Neanderthal genetic blueprint. In this case, just as with the use of elephants to birth mammoths, a Neanderthal could be delivered from a human female, or (perhaps less ethically questionable), a Chimpanzee.

As evolutionary biologist Hendrik Poinar notes, “The reality is it will happen,” ... “Twenty to 30 years is the span people are talking about.”

And what then? When a creature so like us -- but so different -- walked again among us, what then? Dartmouth College ethicist Ronald M. Green's comment is as creepy as it is probing:

“This was a species we competed with,” ... “We would not want to recreate a situation of two competing advanced hominid species.”

We may just find out.

4 comments:

eneve said...

I was reading an article "Gene Machine" - NewScientist, which is basically an article about many different scientist around the world trying to discover the origin of each of our genes.

"We humans have around 400 genes for smell receptors alone, all of which derived from just two in a fish that lived around 450 million years ago."

This article also describes the incredibly complex process of protein folding (how proteins are created from DNA by mRNA), and got me to wondering was this biological machine (one instance of which conveniently is me) Turing complete, was it a computer so to speak?

mijopo said...

I thought they already had regenerated the Neanderthals, who's starring in those Geico commercials?

Erik said...

eneve, who knows? Maybe every process in our bodies can be described by some Turing machine (I'd guess it can), but does this also mean that some Turing machine is generating the process? To put it another way, after the fact, we can describe complex processes in terms of a Turing machine. It's a different question whether a Turing machine caused the process in the first place. Also, if you believe that chemistry, biology and the like are ultimately explicable in subatomic terms, there's this question about the indeterminacy of quantum mechanics.

Erik said...

mijopo, I thought the Geiko dudes were Cro Magnon, or homo sapiens? The tennis playing gives it away.