Welcome Lesley Lancaster, our new postdoc

I am pleased to welcome Lesley Lancaster, our new incoming postdoc, funded by BECC ("Biodiversity and Ecosystem Services in Changing Climate"). Lesley will arrive to Lund in late May or early June, and she will work with me and Bengt Hansson on the population genetics and ecology of range limit evolution, particularly using our favourite model organism: the damselfly Ischnura elegans ("Common Bluetail") as the main study object. Both Bengt and I are very excited about this project and about recruiting Lesley, who will bring with her new skills and perspectives from her previous research.

Currently, Lesley is a postdoctoral scholar at  the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara (California, USA), where she has been since 2009. Her main focus of research has been to reconstruct historical evolutionary processes of adaptation, speciation, extinction and migration using time-calibrated molecular phylogenies of various Californian plant clades. She is also interested in historical habitat tolerances of the unique California chaparral habitat. Her postdoctoral research has resulted in some interesting papers in BMC Evolutionary Biology and Systematic Biology.

Lesley's thesis research was on a quite different topic: maternal effects, reproductive strategies and evolutionary ecology of a colour polymorphic lizard (Uta stansburiana), where she worked in the laboratory of Barry Sinervo at University of California, Santa Cruz (UCSC). Her thesis work also resulted in a number of interesting and impressive publications in American Naturalist, Ecology Letters, Evolution and PNAS. 

Lesley is thus an extremely broad and well-rounded biologist and a very experienced postdoc, who has worked at quite different levels of biological organization, and moved her research focus from studies of individual behaviour and evolutionary ecology, to broader macroevolutionary and macroecological questions. It is for precisely these reasons we are excited to bring her in to Lund; she has both sufficient much in common with our already ongoing research,  yet has many complementary skills that will be of interest to us and our research.

On the antagonistic relationship between sexual selection and assortative mating

Posted by Erik Svensson


It is time for lab-meeting again, and this week we are happy to welcome Machteld Verzijden back from Rutgers University, where she has been working with Jessica Ware. Let's start the lab-meeting with her telling us about her work and the progress made during the visit.

Note the new time: Wednesday March 28 at 13.30 (not 13.00!).


After this, I was thinking we should discuss the relationship between sexual selection and assortative mating, two processes that are often confused and mixed up, particularly in the field of sympatric speciation. Although these processes are by no means totally independent, they are not identical and their population genetic consequences are very different. Moreover, they can counteract each other and hence could be antagonistic.

To understand the finer details of the complex relationship between assortative mating and sexual selection, we'll have to leave the murky shallow waters of "Adaptive Dynamics" and instead to turn to a clear thinker and a population genetic theoretician who knows what he is talking about: Mark Kirkpatrick från Austin (Texas). I was thinking we should read a much-cited papers from Proceedings of the Royal Society, entitled "Sexual selection can constrain sympatric speciation". Below, you will find the Abstract and here is a downloadable link to the PDF:


Sexual selection can constrain sympatric speciation

1. Mark Kirkpatrick^* and 
2. Scott L. Nuismer†

Source: PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES  Volume: 271   Issue: 1540   Pages: 687-693   DOI:10.1098/rspb.2003.2645   Published: APR 7 2004

Abstract

Recent theory has suggested that sympatric speciation can occur quite easily when individuals that are ecologically similar mate assortatively. Although many of these models have assumed that individuals have equal mating success, in nature rare phenotypes may often suffer decreased mating success. Consequently, assortative mating may often generate stabilizing sexual selection. We show that this effect can substantially impede sympatric speciation. Our results emphasize the need for data on the strength of the stabilizing component of selection generated by mating in natural populations.

Former postdoc Sophia Engel got new job

Posted by Erik Svensson

I just got the happy news that our former CAnMove-postdoc Sophia Engel just got a new job as ornithologist for a non-profit organization in Germany. These days when job market in Europe is very tough, it is of course great news to hear that former co-workers get highly qualified jobs that are related to biology (nothing one can count on these days, unfortunately) and in fields close to their heart and interests. On behalf of myself, and hopefully on behalf of all other lab-members and colleagues in Lund, I congratulate Sophia and wish her good luck with her new position!

On density-dependent diversification and speciation in birds

Posted by Erik Svensson


This coming Wednesday (March 21 at 13.30 NOTE TIME!!!!), we will discuss a paper about the (possible) density-dependent slowdown of cladogenesis in birds with the progress of adaptive radiation. It is a paper that was published relatively recently, although it is not entirely new, in PLoS Biology by Albert Phillimore and Trevor D. Price. The title of the paper is:
"Density-Dependent Cladogenesis in Birds"
The authors have used molecular phylogenies from various avian groups to test the hypothesis that diversification rates decline with the progress of adaptive radiation, and as we are approaching the present. Here is the Abstract to the article, which can be downloaded here (PLoS Biology is a "Open Acess"-publisher, which makes everything easier):

Abstract 

A characteristic signature of adaptive radiation is a slowing of the rate of speciation toward the present. On the basis of molecular phylogenies, studies of single clades have frequently found evidence for a slowdown in diversification rate and have interpreted this as evidence for density dependent speciation. However, we demonstrated via simulation that large clades are expected to show stronger slowdowns than small clades, even if the probability of speciation and extinction remains constant through time. This is a consequence of exponential growth: clades, which, by chance, diversify at above the average rate early in their history, will tend to be large. They will also tend to regress back to the average diversification rate later on, and therefore show a slowdown. We conducted a meta-analysis of the distribution of speciation events through time, focusing on sequence-based phylogenies for 45 clades of birds. Thirteen of the 23 clades (57%) that include more than 20 species show significant slowdowns. The high frequency of slowdowns observed in large clades is even more extreme than expected under a purely stochastic constant-rate model, but is consistent with the adaptive radiation model. Taken together, our data strongly support a model of density-dependent speciation in birds, whereby speciation slows as ecological opportunities and geographical space place limits on clade growth.

We meet at 13.30 (not 13.00!) to discuss this interesting article.

Lab meeting March 7: challenges and prospects of quantitative trait studies

Posted by Maren Wellenreuther

For the next lab meeting, we will dive a bit deeper into the discussion that we started last week. At the last lab meeting, we read a paper by Rockman (2012) entitled ‘The QTN program and the alleles that matter for evolution: all that's gold does not glitter‘. The paper points out what has long been known (but forgotten by some): evolution often acts via large numbers of small-effect polygenes, that are on their own almost impossible to detect with the methods available to us. Thus studies are biased towards finding large-effect alleles. But are these representatives of evolution, or are they misleading about the nature of how evolutionary change comes about?

For the next EXEB lab meeting  (7^th of March, start at 13:00 in Argumentet) I suggest we read a review article by Mackay et al. (2009) with the title ‘The genetics of quantitative traits: challenges and prospects’. 

I will bring fika.

reporting from the Animal Behaviour graduate course

Last week Ben Chapman and myself organized a graduate course on Animal Behaviour. This was a first for us, and for Lund, so we were very excited to see it go as well as it did. Here a report from the course.

But first, let’s go back in time about 6 months, when Ben and I went down to gorgeous Portugal to learn new skills at the First IV workshop led by Diane Ebert-May. Here we heard about and learned to put into practice techniques for student-centered learning. I wrote about that in a previous blog. With this in mind, we designed last week’s course, and we have a feeling that we were successful, more on that below.

To remind you, with student centered learning, the students are actively involved in their own learning: students are thinking about the concepts, research questions and discuss these with other students and teachers. This means that we worked hard to provide the opportunity for the students to be active during the classes. Some of the telltale sings of our approach working can be seen in these pictures below.

Apart from us practicing our teaching techniques, we covered a large area of topics, and invited in-house and external experts to the course to provide the students with the view from scientists at the front of their field. These in-house experts were: Michi Tobler & Caroline Isaksson (physiology and behavior), Mathias Osvath (animal cognition), Charlie Cornwallis (sexual selection). We also invited three workshop leaders from outside Lund. These were Dan Franks (university of York), who inspired us to think about social networks in biology and how to analyse them. Niels Dingemanse (Max Planck institute for Ornithology) who has developed methods to analyse animal personality data. Hans Slabbekoorn (Leiden University) led a workshop on acoustic analysis and told us about environmental influences (anthropogenic or natural) on animal communication.

Each of them gave inspiring contributions, and the students, including Ben and I, learned many new things and were inspired to think about our own research from a bunch of new angles.

Thus, from our perspective the course was a success. All Ph.D students completed the course, the content and teaching styles were diverse and the students were actively engaged in their own learning. The anonymous student feedback was also positive. The mean overall course score was 3.94 in a scale between 1 – 5 where 4 = Excellent! Interesting and covered all relevant information. Students scored the overall difficulty of the course at 3.13, where 3 = The right level of difficulty. We also asked students anonymously in the evaluation whether they would recommend this course to a colleague. 100% of respondents replied ‘Yes’. Our aim was to teach the course in an active learning style (see Handelsman et al. 2004, Science), and we encouraged all contributors to involve discussions and student-centred learning techniques where possible. This style received very positive feedback from students: In response to the two questions “Comments generally about the course/What did you like about the course?” 14/16 completed feedback forms spontaneously praised the interactive approach and our use of discussion within classes to facilitate learning. Students were very positive about the opportunity to interact socially with one another and also the visiting lecturers, and enjoyed the research talks. The highest feedback score was for the ‘speed dating activity’ where students had 2 minutes in pairs to come up with an interesting collaboration. After the 2 minutes had passed students switched to a new partner and designed a new collaboration. This allowed everyone to apply their creative skills to generate new and exciting research questions and worked very well.

Critical feedback from the students

We also received important feedback on how we could improve the course should it run a second time. Many students found the data analysis workshops too intense and difficult, which is reflected in their lower mean scores (~3/5) compared to the more general classes. There were also requests for more examples from the invertebrate literature. Both of these issues raised could easily be addressed; in the first case by modifying the workshops to make them more inclusive and less software oriented; in the second case we could include a contributor working with an invertebrate system.

We also received positive feedback from the staff and visiting speakers involved in the course.

Ben and I would like to thank all the collaborators, in-house and external, for working so hard with us to make this course a success. The effort clearly paid off!

Below the statistics on the feedback:

Scoring: 5 = This was the best hour and a half of my waking life; 4 = Excellent! Interesting and covered all relevant information; 3 = Good, but could be improved; 2 = Not so inspiring; 1 = An effective substitute for water boarding

Lab meeting Feb 29: genetic basis of adaptation

Posted by Jessica Abbott

For the next EXEB lab meeting (Wednesday February 29), I suggest we read a recent paper from Evolution about the genetic basis of adaptation.

Rockman, M. V. 2012. The QTN program and the alleles that matter for evolution: all that's gold does not glitter. Evolution 66(1):1-17.

Abstract: The search for the alleles that matter, the quantitative trait nucleotides (QTNs) that underlie heritable variation within populations and divergence among them, is a popular pursuit. But what is the question to which QTNs are the answer? Although their pursuit is often invoked as a means of addressing the molecular basis of phenotypic evolution or of estimating the roles of evolutionary forces, the QTNs that are accessible to experimentalists, QTNs of relatively large effect, may be uninformative about these issues if large-effect variants are unrepresentative of the alleles that matter. Although 20th century evolutionary biology generally viewed large-effect variants as atypical, the field has recently undergone a quiet realignment toward a view of readily discoverable large-effect alleles as the primary molecular substrates for evolution. I argue that neither theory nor data justify this realignment. Models and experimental findings covering broad swaths of evolutionary phenomena suggest that evolution often acts via large numbers of small-effect polygenes, individually undetectable. Moreover, these small-effect variants are different in kind, at the molecular level, from the large-effect alleles accessible to experimentalists. Although discoverable QTNs address some fundamental evolutionary questions, they are essentially misleading about many others.

We'll start at 13.00 in Argumentet.