Neandertals in Our Midst

The commercials featuring the Geico caveman made it seem as if a Neandertal could readily interact within a Homo sapiens society.... we may soon find out if that is true.

Recently, scientists at the Max Plank Institute of Evolutionary Anthropology in Leipzig Germany announced that they had completed the sequencing of the Neandertal genome.

Neandertals went extinct around 30,000 years ago - most likely because of an untimely interaction with the Cro-Magnon, our early ancestors. As was the case with most species on the planet, Neandertals did not fare well from their encounters with us. For some time scientists have believed that it may have been possible that Neandertals simply bred into the Cro-Magnon population and the two became genetically integrated. Based on the work of these German scientists, it is now clear that this did not happen. There is no significant evidence of a transfer of Neandertal genes into our species.

While nature intends for extinction to be permanent, our mastering of the molecular world has made it possible to bring some species back to life. Wolly mammoths, the dodo bird, and passenger pidgeons have all been nominated as species to be returned to the surface of the planet. We can now add a new species - the Neandertals.

Once the genomic analysis is complete, it may be possible to transplant Neandertal DNA into a chimpanzee, or even human, ovum. Since there is very little genetic difference between these three, there should be relatively few developmental probems. In fact, it is estimated that this could occur within the next few years at the nominal cost of around $30 million.

So what would we do with these Neandertals? We should decide that before we begin. Our initial instinct may be to put them in a zoo. But we should be careful about that decision. For although we may consider ourselves to be the evolutionary favorite - we may have just gotten lucky the first time. We now know that Neandertals possessed the gene for speech, FOXP2, and they had a larger brain size than ours, and had the at least the beginnings of culture. They may give us a serious run for our money this time around. Who knows, maybe this time they will let us integrate into their culture..... or maybe not.

The Return of the Sloth?

Around 10,000 years ago, in the region of the United States now known as the Appalachians, lived one of the most impressive mammals ever to inhabit North American. With a height of over 8 feet, and weighing up to 800 pounds, the giant ground sloth ( Megalonyx jeffersonii to scientists) was a formidable sight. However, the ground sloth, like most large land mammals in North America, went extinct. Why is still a mystery to scientists - some believe that it may have been the result of a change in climate, others suggest that it may have been from predation by humans.

Such is the case for many species, and it is the basis of Darwinian natural selection. Those species that have the genetic variation to adapt to a changing environment do, and those that do not go extinct. Unfortunately, humans have been changing the environment a little faster than most species would like. Many ecologists and biodiversity experts believe that we are experiencing a mass extinction event unlike any in the past 65 million years. And, until recently, we had few choices to prevent the extinction of a species - we could either put it in a zoo, or try to conserve its natural habitat. While both have had some success, most of the news from the conservation front is not good.

Some have asked whether it may be possible to clone extinct animals using the DNA from frozen tissues. Until recently, the majority of attempts to do this have failed - mostly because the DNA was damaged by the process of freezing. DNA is a durable, but also delicate, molecule. Its structure protects it for long periods of time, but even slight damage to its information-containing bases can be troublesome. That may have changed with a discovery by Teruhiko Wakayama, a Japanese developmental biologist. Wakayama has found a way to use frozen DNA in a cloning process. His process appears to reduce the influence of damaged DNA, allowing previosuly unsuitable tissues to be used in the cloning process. Once a cell line is cloned, it could be used to revive an extinct species.

For the ground sloth, passenger pigeon, and the dodo bird, this may be the resurrection that the species needed. Not only could we finally right a terrible wrong in our human history, we may be able to prevent (or at least postpone) the extinction of some species that are currently struggling for survival. Of course, no one is actually (yet) suggesting that we can bring back a giant sloth, but if we can perfect the process, then someday hikers along the Appalachian Trail may have more to deal with than just brown bears.


Additional References:

Wakayama's 2008 paper in PNAS