Thursday, June 11, 2009

"The Origin of Species - 150 years later"

I am currently at the Marin Biology Research Station in Kristineberg (Fiskebäckskil) in Bohuslän att symposium in celebration of Charles Darwin. This year (2009), it is 150 years since "The Origin of Species" was published, and 200 years since Darwin was born. To celebrate the memory of Darwin, Hans Ellegren (professor of evolutionary genetics in Uppsala) and Staffan Ulfstrand (professor emeritus of animal ecology, also from Uppsala) has arranged a symposium in the beatiful archipelago on the swedish west coast. Funding for this meeting comes from The Wennergren Foundation. Unfortunately, this meeting was only open for a small group of invited people, apart from the speakers, so here is a little report from the first day.

The theme of today has been theory and genetics of speciation, with some great contributions from evolutionary theoreticians Michael Turelli (University of California, Davies) and Sergey Gavrilets (University of Knoxville, Tennesse). Turelli talked about Haldane's rule and the genetics of postzygotic isolation, and Gavrilets presented models for the tempo and mode of adaptive radiations. Although some of these topics have been presented before by these two leading theoreticians, it is always nice to get un update.

Gavrilets have apparently got a big grant from the National Science Foundation (NSF) to set up a centre for mathematical and biological synthesis in Knoxville, similar to the ecological synthesis centre in Santa Barbara and the evolutionary synthesis centre in North Carolina. Worth checking up: there will be funding opportunities for both postdocs and workshops.

More "naturalistic" talks were given by Trevor Price (University of Chicago) and Jim Mallet (London) about bird and butterfly speciation, respectively. Trevor presented some idéas and phylogenetic patterns on bird diversification in the Himalayas, which challenges the current ecological speciation paradigm, which has almost been taken a bit too much for granted based on a few well-investigated model systems such as the Galápagos finches. Mallet questioned the views by Ernst Mayr about the reality of species and argued that Darwin's view on species was more realistic than some of the views that were advocated by Mayr and other architects of the so-called "Modern Synthesis" in the 1940'ties. In particular, Mallet argued that some of their idéas about reproductive isolation evolving to protect the "genetic integrity" of species relied on naive group-selectionism.

Two swedish contributions were by Kerstin Johannesson (parallell evolution of reproductive isolation in Littorina-snails) and Anna Qvarnström (genetics of speciation in Ficedula-flycatchers). In general, I would say that this meeting has been good to get updated on the classical concepts and discussion topics, although there has not been many surprising news. In that sense, I have the feeling that perhaps the field of speciation might have reached a plateau (perhaps temporary) where it has now entered what science philosopher Thomas Kuhn would call "normal science" or "problem solving". Perhaps I am wrong, but I have the distinct feeling that we need some new idéas to focus on, as the classical allopatry-sympatry controversy seems to fade away and people loose interest. To me, the most thought-provoking talk today was the one by Trevor Price, although I do not necessarily agree with everything he had to say. In any case, his book "Speciation in birds" is highly recommendable.

Hopefully, I will be able to publish another bloggpost tomorrow about the genomic aspects of speciation, which will be discussed tomorrow. Food here is excellent, by the way.


  1. It sound slike you are having a great time over there, Erik!
    Two questions: what is the alternative explanation Jim Mallet is proposing to the emergence of reproductive isolation? and can you develop a bit what Trevor Price is pushing forward on ecological speciation? I recall the system he is working on in Himalaya has more to do with ring speciation than ecological speciation, but mabe he has been working on that as well... Anyway, you made me very curious, but maybe you could post another more detailed summary on this question when you get back... Lately, the ecological speciation paradigm seems to have been the most dynamic topic in the field of sepciation, both theoretically and empirically... But i agree with your insgiht on the matter, it seems to have reached some kind of a plateau, and the sympatric7allopatric debate does not interest a lot of people anymore, which in a way i am glad of...

  2. Fabrice:

    Mallet had a recent review in Biol. J. Linn. Soc. where he develops his criticism of Ernst Mayr and the "reality" of species. Mallet argues, like Darwin, that there is a continuum from morphs, ecotypes/races to full species. He discussed hybridization in animals, and argued that the common occurence of hybridization between "good" species is an indication that species might not be as real as Mayr argued, and that speciation can happen easy. Gavrilets questioned this, and argued that the common occurence of hybridization might actually indicate the opposite: that speciation is not that easy. I do not know what species concept Mallet likes, altough it seems like something of a genic version of the species concepts like Wu have argued (perhaps!).

    Trevor argued, I think correctly, that the classical cases of adaptive radiations (cichlids, sticklebacks, Darwin's finches) on habitat "islands" (real islands, lakes) are not representative for most speciation events which took place on large continents. Moreover, insect-eating birds like warblers, do not seem to speciate as easily as seed-eating birds or sticklebacks or cichclids. It might have to do with their feeding niches not being as discrete as the classical cases. Trevors current position, it seems, is that ecological speciation might have been somewhat overrated. More soon.

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  4. Erik and Fab,
    Here is the reference to Mallet's paper. I read it the day it came out, but you guys know how I enjoy this stuff. Here is the paper (I can't figure out how to make a link in a comment):

    Mallet, J. 2008. Mayr’s view of Darwin: was Darwin wrong about speciation. Biological Journal of the Linneaen Socety 95:3-6

    Here is Mallet's species concept:

    Mallet, J. (1995). A species definition for the modern synthesis. Trends in Ecology and Evolution 10: 294-299

    With regard to Mallet, Mayr, and Darwin: I always have felt that Darwin got more right than Mayr admitted. It was great to see Mallet (bravely) put this into print. As much as I admire Mayr (a lot), my ideas on what a species is, and how species arise, are more in line with Darwin (and Mallet).

    Time for bed.