The short answer: about 9 million, not counting bacteria. That’s according to a new paper in PLoS Biology by Camilo Mora et al. (see also the perspective by Robert May in the same issue; both paper and perspective are free, and you should definitely read Bob’s one-page piece). The issue of how many species inhabit […]
One of the big controversies in the study of speciation involves the spatial scale of the process. Can an ancestral species split into two descendants within a single small area (“sympatric speciation”), or do populations have to be geographically isolated before they can evolve into new species (“allopatric speciation”)? Clearly the formation of new species […]
In case you didn’t know, Scientific American has just started a whole herd of “blogs”—39 of them—and you can find the list here. There are some old favorites, some new ones, and even some group websites. If you’ve followed these “blogs” in their previous incarnation, feel free to list your favorites below. I’d like to […]
Yesterday I presented some photographs and descriptions by biologist Dennis Hansen of his work on the isolated island of Mauritius. That only scratched the surface of the amazing biology of the endemic species on this island, and I want to finish up this brief lesson with some more show-and-tell. Dennis also sent me an reallly […]
I’ve rarely seen a critique this strong in the reviewed scientific literature. It’s about Wolfe-Simon et al.’s paper in Science suggesting that a bacterium could incorporate arsenic instead of phosphorus in DNA and biomolecules. Simon Silver and and Le T. Phung take strong issue with this in a piece in the “current controversies” section of […]
Today’s New York Times reports the death, at 89, of Rosalyn Yalow, the second woman to win the Nobel Prize for Medicine and Physiology. (Yalow won in 1977; the first, Gerty Cori, got hers thirty years earlier. There have been eight female winners since Yalow). If you want to see how much tougher it was […]
Insofar as I have any “philosophy” about how I do my work, it’s this: keep experiments simple. I’ve always tried to do experiments sufficiently uncomplicated and easy to understand that the results—one way or the other—would be clear-cut enough to not require (or barely require) statistical analysis. I’ve taught my students this notion, too, and […]
One of my favorite “proofs” of evolution is the recurrent laryngeal nerve (RLN)—the nerve that innervates the larynx from the brain, helping us speak and swallow. It takes a very circuitous course, looping from the brainstem down around the aorta and then back up to the larynx. Here’s its course in humans: It’s a prime […]
A few days ago I used the term “true bug” when referring to a specific order of insects. This engendered some confusion, as a few people didn’t know the difference between “bugs” in common parlance and “true bugs” in scientific parlance. You will want to know the difference, and Alex Wild explains at Myrmecos: An […]
This piece from Wired Science, “The mass extinction of scientists who study species.” came out a while back, but I was thinking about this problem last night. The genus Drosophila (“fruit flies” or “vinegar flies”), on which I work, has been the most important group of organisms for the study of evolutionary genetics. Indeed, much […]
