by Greg Mayer
In today’s Science Times, Carl Zimmer has a nice article on Darwin’s favorite birds, pigeons. “Whoa”, you say, “Pigeons? Don’t you mean finches?” No, pigeons it is. While we’ve grown accustomed to associating Darwin’s name with the 15 or so finches of the Galapagos Archipelago (plus one species on Cocos Island), the term “Darwin’s finches” was coined by the British ornithologist Percy Lowe in only 1936, and popularized by David Lack in his 1947 monograph Darwin’s Finches. Darwin collected and observed finches in the Galapagos, and wrote about them, especially in the Voyage of the Beagle, but he spent many more years studying pigeons, and learned a great deal from them.
Darwin was greatly interested in the work of plant and animal breeders in creating and modifying domestic varieties, and the vera causa (“true cause”) of artificial selection was an important part of Darwin’s argument for the efficacy of natural selection. Darwin corresponded widely with breeders, and gleaned their magazines, collecting a wide variety of facts on the nature of variation and the response to selection. He included some of this in the Origin, but most extensively in Variation Under Domestication (1868, 2 vols.). Darwin chose pigeons as the domestic species to study most closely, keeping them himself at Down House.
The occasion for Carl Zimmer’s piece is a paper in press by Michael Shapiro and colleagues, who have instituted a very interesting program of research on the genetic basis of evolutionary change in domestic pigeons; like Darwin, they are relying on the help of breeders. Early results indicate that all domestic pigeons arise from the wild rock dove, and that certain characteristics, such as head crests, have arisen multiple times, but on the same genetic basis. There’s a very nice set of photos online accompanying the piece.
Darwin, C. R. 1868. The variation of animals and plants under domestication. London: John Murray. (illustrations plus link to full text)
Shapiro, M.D. et al. 2013. Genomic diversity and evolution of the head crest in the rock pigeon. Science, in press. (abstract)
Sulloway, F.J. 1982. Darwin and his finches: the evolution of a legend. Journal of the History of Biology 15:1-53. (pdf)