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)
Hey! How can these be early results when that is what Darwin himself said?
Early results of their genetic work– as Zimmer notes, this supports Darwin’s conclusion. Darwin took pains to show that the variability of pigeons was not due simply to crossbreeding of different wild species.
GCM
It is nice to see that, like Darwin’s claims regarding the single-species origin of all varieties of domestic pigeons, the ‘early results’ that Zimmer mentioned confirm the conclusions that one of Darwin’s steadiest sources, Edward Blyth, communicated to Darwin on April 3, 1856, that ‘all domestic pigeons arise from the wild rock dove; or, better, to use Blyth’s own words:
“The more I see of domestic Pigeons, the more obvious becomes the conclusion, according to my judgment, of their having all descended from the livia (or barely separable intermedia, &c.); and I think the voice quite attests this, quite as decidedly as with domestic fowls. Some difference of voice there undoubtedly is, among the races; but what is that amount of difference, compared with the distinct coo of any really different species? It is indeed surprising what varieties of cooing there are among the various wild or true species of Columbidæ; in all cases an unmistakeable Pigeon’s voice, yet how different one species from another, & comparatively how very similar the coos of the different domestic races! Then their pairing so indiscriminately, however different the races!”
This quotation is taken from one of several “Notes for Mr. Darwin” that Blyth sent to Darwin in 1856-7; Blyth was not only studying pigeons himself and publishing on the subject, but was also sharing his thoughts with Darwin and sending him specimens as well. It is unfortunate that Darwin failed to acknowledge that Blyth had arrived at the conclusion of the single=species origin of domestic pigeons, but even more unfortunate that for so many people, Dasrwin’s is the only name to come to mind when it comes to assigning credit for early evolutionary insights.
Hey! How can these be early results when that is what Darwin himself said?
And let’s not forget chickens! IIRC, Darwin dedicated a whole chapter on them in his 1868 work, and kept chickens as well at Down House. Thank you for the link to the article.
Nice article!
FWIW, Rock Doves are now officially Rock Pigeons. (It was controversial.) In birding, common names are standardized…
http://10000birds.com/requiem-for-the-rock-dove.htm
I hadn’t noticed, even though it’s been a decade! As I’ve noted before here at WEIT, though, I’m fond of common names, which may differ from Standard English Names; the latter are enunciated by the AOU, BOU, and influential field guide authors, while the former are what people actually call them. Thus for me Falco sparverius is a sparrowhawk in the U.S., a killy-killy in the Caribbean, and only an American Kestrel when writing for a journal that uses Standard English Names.
UPDATE: It seems that the BOU and the IOC have gone back to Rock Dove. Since the stated reason for the AOU’s change to Rock Pigeon was to conform to the BOU, I suppose the AOU will now change back to Rock Dove as well.
GCM
Ha, ha! I hear ya! I still say sparrowhawk, too, and English sparrow rather than the blah “House.” And by those standards, then, the birds in question here are “flying rats” on my birding forum… 😀
And birders there are still using Rock Dove, too. That change really flew under the wire, so to speak. Probably because pigeons rank so low with most birders.
I always thought it’d be fascinating to raise them.
I am surprised that you have not mentioned the pope’s dove being attacked by a seagull.
When I go to the Marine Biological Laboratiory in Woods Hole, Massachusetts to lecture in a course, they often have historical photos on the wall. Some of them are of a dramatically white-bearded man named Charles O. Whitman, a University of Chicago professor who was also a famous director of the MBL over 100 years ago. (In fact the room in which I lecture was named Whitman Auditorium until recently, when it was renamed after a recent donor). I was interested to see that Whitman worked on pigeons. I wondered what he had actually done.
This post led to me finally looking him up on Wikipedia and other web resources. He seems to have done a lot of very good and careful work on morphological variation and color variation, and trained a lot of students on whom he was a great influence. Then he proceeded to say that the results were all best interpreted by orthogenesis instead of Darwinian mechanisms, and that they were not a good fit with Mendelian variation.
This was unpopular even in his time. He died in 1910 and his work was quickly forgotten, and he was remembered mostly as a director of the MBL.
I once found to some surprise dodos are relatives of pigeons, and now looking again I see that that idea had been kicked around beginning in 1840s. I don’t see any mention on Wikipedia that Darwin had any thoughts on that, but thought I’d ask here.
Darwin mentioned dodos a few times, but as an example of a southern flightless bird, island endemic, and victim of rapid extinction. Don’t know of any mention by him of their relations, but check this to look further:
http://darwin-online.org.uk/content/search-results?freetext=dodo
GCM
Thx!
I would like to thank you for the efforts you have put in penning this site.
I really hope to check out the same high-grade blog posts by you in the future as well.
In fact, your creative writing abilities has motivated
me to get my own website now 😉