Thie paper below is the culmination of research started at least ten years ago in Chicago, but, due to various glitches and re-doing the research in a more thorough way, it didn’t see light for a decade. The paper also represents a collaboration between several investigators, starting with my last NIH grant, but was delayed because of the need to do DNA sequencing (which I couldn’t do), and then the arrival of better, faster, and cheaper DNA-sequencing methods, which allowed us to sequence 20 million bases of DNA for the final paper.
It’s finally appeared as an “early online” paper in Genetics, and will be in the journal soon (I hope). Click on the screenshot to see the online version (pdf here), which isn’t as spiffy-looking as the published version will be. Since I’m not doing any more research with my own hands, this represents what I think will be my last research paper, but perhaps not my last refereed scientific paper.
I’ll explain the results as briefly as I can when the paper appears in final form, but if you want to read it now, it’s free. I want to say two things, though.
First, I think it’s a really cool experiment, and a good way to go out. It’s the sort of experiment that every evolutionary geneticist thinks of, wants to do, but realizes that it’s dicey because it takes a long time and you might not get the answer before applying for your next grant. Fortunately, this was a major part of what I knew would be my last NIH grant, so I was under no pressure to finish the experiment in the three-year granting period. The question involved was this: if you thoroughly mix two different species of Drosophila, producing a “hybrid swarm” that has the DNA and cytoplasm of both species in equal proportion, what happens to that swarm? Does it evolve into a new species? Or does it revert back to one or the other parental species, and, if so, does it revert to the same species over and over again when you make replicate swarms? And if there is such reversion, how much is reflected in morphology, behavior, and DNA sequence? (That is, does the evolved swarm superficially resemble one of the parental species but still contains DNA from both species?) Or does the admixture produce a swarm that is not a “new species” (like the hybrid parrots that the Washington Post got wrong), but simply a mixed population of mongrels that isn’t reproductively isolated from its parents?
The answer, it turned out, was very clear, repeatable, and quite interesting. But stay tuned.
Second, my very first real research paper, published in 1972 based on my undergraduate research at William and Mary—and also on speciation—appeared in Genetics as well, which is a very good journal. (That paper is free online here.) So there’s been a pleasing symmetry in my research career.