Population genomics gets real in Drosophila

There has been lots and lots of talk about “population genomics” in the last few years. For microbes, people have been doing this type of genome wide survey within populations for some time. But for multicellular organisms there have been only a few studies and most of these were limited in scope. Now comes a in depth study of Drosophila simulans published in PLoS Biology. This project, led by colleagues of mine at UC Davis (David Begun is first author, Chuck Langley is senior author) did “light” whole genome sequencing (at the Washington University Genome Sequencing Center) of seven lines of D. simulans and one line of D. yakuba.

There is lots of interesting population genomics, population genetics and evolutionary analysis in this paper. If anyone out there is interested in personal genomics or human population genomics in any way, it is worth checking out this paper as a model for what can be done in multicellular eukaryotes.

Human Evolution and Neanderthals

Well, I suppose everyone should have seen this coming. An announcement has been made of plans to sequence the genome of a Neanderthal. The plan is to take DNA extracted from a Neanderthal fossil, and sequence it using a relatively new method from a company known as 454 Life Sciences.

I am torn about this project. Yes, it is cool to read DNA sequence from an extinct species, especially one that has not been around for some time and one of direct relevance to understanding human evolution. On the other hand, I would personally find it much more interesting to try and sequence an ancient Homo sapiens first. This is because the comparison of the Neanderthal to modern humans may not be the right comparison. It would be better to first compare an ancient Homo sapiens sample to modern humans, maybe with both being done with the same methods to be used in the Neanderthal study. This would be for two reasons. First, we do not really know how well the method(s) they are using work. And second, if the methods work well, it is possible that some of the differences they observe would actually be due to degradation or damage to the DNA sample. Therefore, if they simultaneously did work on an ancient Homo sapiens they might better be able to calculate which differences are do to real differences in the Neanderthal DNA and which are due to damage to the sample.

Assuming they do something like this and they are able to detect differences in the Neanderthal genome. What then? In the end, the major area of interest will be population genetic analyses trying to figure out how long Homo sapiens and Neanderthals were separated for and whether there was any interbreeding. To figure this out, they will need more Neanderthal samples and ancient human samples. Nevertheless, it is always good to do something that brings attention to the public for scientific research.