Tuesday, December 22, 2009

Merry Christmas and a Happy New Year!

On behalf of myself and my research laboratory, I wish you all (PhD-students, undergraduates, postdocs and senior collaborators) a Merry Christmas and a Happy New Year! Although the official celebration of the "Darwin Year" is now over, for us evolutionary biologists every year will indeed be another "Darwin Year", including 2010. I am looking forward to some exciting new research news, both in this lab and in the scientific community as a whole. Take care!

Tuesday, December 15, 2009

WWDD (What Would Darwin Do?)

Hello Everyone! On this blog we've discussed the value of publishing in Open Access journals at least a couple times, and it general the idea has received strong support (including from me, if I remember correctly). Alan Moore (who was Tom's Ph.D. opponent) just published an article in support society-based journals. As a long-term member of many societies, I found Moore's article spoke to many things that are important to me, and he makes excellent points. For example, someone always pays, even if the article is freely available. More importantly, supporting societies has a lot of academic and cultural value. We all enjoy and benefit from the ESEB meetings, and from the promotion of science (in the USA, we need all the help we can get getting facts about Evolution out!!!!!!). Another interesting point: we provide free reviews to support academic societies (a reasonable volunteer contribution), but we also provide free reviews to open access, society-less journals, and are thereby padding the bottom line of the publishing industry (people who almost certainly make more money than I do). Why do this expert service for free for industry? I may not review for society-less journals any longer, unless they pay me.

I remember a couple years ago there was a talk at Lund about Open Access and its virtues from the perspective of a librarian. It was an excellent, convincing talk, and I enjoyed it. Afterwards, someone asked about the societies and how they fit into this. The answer, which did not satisfy me, was that they'd have to "do something else" (I'm quoting from long memory here -- at any rate, the response was terse and unsympathetic to the concerns of society-based journals). I agree with Moore that the academic societies are of extraordinary value to us as researchers and academics (more than most realize, I would venture), and deserving of our support in terms of finances and as a first choice when be publish.

Now, let me cover my head and run....

Sunday, December 13, 2009

On ecological speciation, tempo and mode of evolution

The coming week's lab-meeting (16 December 2009), will be the last one for 2009. Due to teaching obligations, I would like the meeting to start somewhat later than usual, at 10.30. The topic of this week's lab-meeting will be speciation, and we will discuss two papers published in 2009 in and Nature and Science (abstracts are provided below):

Phylogenies reveal new interpretation of speciation and the Red Queen

Chris Venditti1, Andrew Meade1 & Mark Pagel1,2

(Nature advance online publication)

Evidence for Ecological Speciation and Its Alternative

Schluter Dolph

Science (2009) 323: 737-741

These two papers are interesting, because they reflect radically different views on the causes of speciation and the drivers of speciation processes. I therefore thought it would be interesting to discuss them with this in mind, and contrast their different underlying viewpoints against each other. Who is correct and who is wrong? Or are both correct, and if so, in what domains?

We will thus meet at 10.30 in "Darwin" on Wednesday 16 December. Any fika-volunteer?

Abstracts follow below:

Chris Venditti1, Andrew Meade1 & Mark Pagel1,2

Phylogenies reveal new interpretation of speciation and the Red Queen

The Red Queen1 describes a view of nature in which species continually evolve but do not become better adapted. It is one of the more distinctive metaphors of evolutionary biology, but no test of its claim that speciation occurs at a constant rate2 has ever been made against competing models that can predict virtually identical outcomes, nor has any mechanism been proposed that could cause the constant-rate phenomenon. Here we use 101 phylogenies of animal, plant and fungal taxa to test the constant-rate claim against four competing models. Phylogenetic branch lengths record the amount of time or evolutionary change between successive events of speciation. The models predict the distribution of these lengths by specifying how factors combine to bring about speciation, or by describing how rates of speciation vary throughout a tree. We find that the hypotheses that speciation follows the accumulation of many small events that act either multiplicatively or additively found support in 8% and none of the trees, respectively. A further 8% of trees hinted that the probability of speciation changes according to the amount of divergence from the ancestral species, and 6% suggested speciation rates vary among taxa. By comparison, 78% of the trees fit the simplest model in which new species emerge from single events, each rare but individually sufficient to cause speciation. This model predicts a constant rate of speciation, and provides a new interpretation of the Red Queen: the metaphor of species losing a race against a deteriorating environment is replaced by a view linking speciation to rare stochastic events that cause reproductive isolation. Attempts to understand species-radiations3 or why some groups have more or fewer species should look to the size of the catalogue of potential causes of speciation shared by a group of closely related organisms rather than to how those causes combine.

Schluter Dolph

Natural selection commonly drives the origin of species, as Darwin initially claimed. Mechanisms of speciation by selection fall into two broad categories: ecological and mutation-order. Under ecological speciation, divergence is driven by divergent natural selection between environments, whereas under mutation-order speciation, divergence occurs when different mutations arise and are fixed in separate populations adapting to similar selection pressures. Tests of parallel evolution of reproductive isolation, trait-based assortative mating, and reproductive isolation by active selection have demonstrated that ecological speciation is a common means by which new species arise. Evidence for mutation-order speciation by natural selection is more limited and has been best documented by instances of reproductive isolation resulting from intragenomic conflict. However, we still have not identified all aspects of selection, and identifying the underlying genes for reproductive isolation remains challenging.

Sunday, December 6, 2009

No lab-meeting this week (9/12)

Due to several other meetings and committments on my side, I am afraid we'll have to cancel the planned lab-meeting this Wednesday (9 December). I will be present in the Ecology Building the whole day, however, in case you need to talk to me in between the meetings. I hope we can have a regular lab-meeting the next week, before the Christmas break (16 December), in case everybody is around then. Please do not hesitate to e-mail me with suggestions for papers to read and discuss!

Friday, December 4, 2009

On scientific "peer-review"

You got to watch this, it is wonderful! Needless to say, in my position as professor and PI, I often identify myself with AH. Enjoy and watch this funny video!