Workshop on "Behaviour and Speciation" in Oslo

This is a quick greeting and update from Oslo (Norway), where I have participated in a very stimulating research workshop entitled "Behaviour and Speciation", funded by FroSpects and organized by Glenn-Peter Saetre at CEES (Oslo). There were a number of interesting talks by invited speakers, including from Ole Seehausen, Lee Dugatkin, Darren Irwin and Anna Qvarnström, to mention only a few. It was nice to meet friends and colleauges like Darren who I have not seen for ten years, i. e. since he was postdoc in Lund.

It was also nice to meet former PhD-student Fabrice Eroukhmanoff (see picture above), who seems to be doing very well in his new research group and who now works in transgressive hybridization in a homoploid hybrid species of Passer-sparrow and its effects on various phenotypic traits, including beak morphology and beak allometry. Fabrice, Glenn-Peter and several others from the "Sparrow-group" gave several interesting talks about the ongoing work in this fascinating system where genomic, phenotypic and ecological data are now being put together to reveal a complicated but interesting speciation history.

I am writing this post from Fabrice's apartment in Oslo, where I am staying two nights before continuing to North Carolina and the NESCent-meeting about "Environmental determinants of selection". I was of course also pleased to hear that EXEB lab-member in Lund Jessica Abbott have been shortlisted for interview in her application for a "Startup Grant" for junior researcher to the European Research Council (ERC). Well done! An impressive achievement to make it this far, irrespective of the outcome during the interview in Brussels in April, I think.

"Target Review" in Journal of Evolutionary Biology about hybridization and speciation and a comment

Posted by Erik Svensson

In the latest issue of Journal of Evolutionary Biology there is a so-called "Target Review" by a large group of evolutionary biologists entitled: "Hybridization and speciation".  This review, as well as the comments on it, are published "Open Acccess", meaning that anyone can read and download them, even if you are not in a university library. One of the co-authors of this multi-authored paper is by the way Fabrice Eroukhmanoff, former PhD-student in Lund and past member of the EXEB lab, and currently postdoc in Oslo (Norway).  Below is the Abstract:

Abstract

Hybridization has many and varied impacts on the process of speciation. Hybridization may slow or reverse differentiation by allowing gene flow and recombination. It may accelerate speciation via adaptive introgression or cause near-instantaneous speciation by allopolyploidization. It may have multiple effects at different stages and in different spatial contexts within a single speciation event. We offer a perspective on the context and evolutionary significance of hybridization during speciation, highlighting issues of current interest and debate. In secondary contact zones, it is uncertain if barriers to gene flow will be strengthened or broken down due to recombination and gene flow. Theory and empirical evidence suggest the latter is more likely, except within and around strongly selected genomic regions. Hybridization may contribute to speciation through the formation of new hybrid taxa, whereas introgression of a few loci may promote adaptive divergence and so facilitate speciation. Gene regulatory networks, epigenetic effects and the evolution of selfish genetic material in the genome suggest that the Dobzhansky–Muller model of hybrid incompatibilities requires a broader interpretation. Finally, although the incidence of reinforcement remains uncertain, this and other interactions in areas of sympatry may have knock-on effects on speciation both within and outside regions of hybridization.

The Target Review is, as usual for these types of invited reviews,  followed by a number of comments, some of them critical, by several evolutionary biologists, including myself. My comment can be found here and is entitled: "Beyond hybridization: diversity of interactions with heterospecifics, direct fitness consequences and the effects on mate preferences".  There are also contributions by Nick Barton, Servedio, Hermisson and Dorn, Seehausen, Björklund and Shaw and Mendelson, to mention only a few comments of what seems to be an interesting discussion around a controversial topic, namely the role of hybridization in speciation. Enjoy!

Merry Christmas and Happy New Year 2012!

 Another year has soon passed, and I wish to say Merry Christmas and a Happy New Year to all of you involved in research in lab. This includes both those of you who are currently in Lund, and those of you who are elsewhere in the world, such as in exotic countries like Norway and Australia.

The pictures above come from the Christmas Meeting in the new Evolutionary Ecology Unit, which was held last week. After talks in the afternoon by several group members and other colleagues in the new unit, it was time for the traditional Swedish Christmas Table, or "Julbord" As you see, Jessica Abbott participated too, after several years of exile in Canada and Uppsala. Jessica will start her new position in Lund in January 2012, after receiving her "Junior Project Grant" from Vetenskapsrådet in 2011. Tina Karlsson also participated, and she will leave to start her postdoc in Finland (Helsinkki) in May 2012.

The year 2011 was an extremely successful year for our lab, in terms of succesful grant applications. Apart from Jessica obtaining a VR-grant and Tina getting a postdoc-grant from VR, Fabrice Eroukhmanoff obtained an EU/Marie Curie postdoc in December, and Machteld Verzijden got extension on her postdoc from the Wennergren Foundation. Considering the severe competition for grants these days, I am both amazed and proud of these achievements of you guys. And you should be as well, of course.

The year 2011 was also  successful in terms of publishing, with nice papers in leading journals, such as Animal Behaviour, BMC Evolutionary Biology, Heredity, Evolution, Journal of Evolutionary Biology, to name a few. We are clearly doing work that is interesting and relevant, and I have the feeling we are moving in the right direction to be even more succesful in the coming years.

Once again: Merry Christmas and enjoy the break! See you in 2012!

Congratulations to Fabrice Eroukhmanoff for obtaining postdoctoral EU-fellowship ("Marie Curie")

Former PhD-student Fabrice Eroukhmanoff, who is currently postdoc at CEES in Oslo (Norway) has apparently obtained a postdoctoral scholarship from the European Union through the "Marie Curie"-programme. As he recently obtained a two-year postdoctoral scholarship from the Swedish Research Council (VR), this means that he can stay longer in Oslo and be able to do more research, before possibly returning to Sweden.

On behalf of myself, as proud former advisor, and the rest of us, I wish to congratulate Fabrice for yet another impressive achievement. Well done!

Happy New Year!

I hereby wish all my co-workers (students, PhD-students, postdocs and colleagues) a Happy New Year 2011! I certainly hope that the new year will be as succesful as the previous was, for many of us. Apart from several good publications in excellent journals (BMC Evolutionary Biology, Evolution, J. Evol. Biol., TREE to mention only a few) I would also like to highlight some other great highlights (to me personally):

1. Kristina Karlsson succesfully defended her PhD in November and have already published most of her thesis-papers. Well done!

2. Fabrice Eroukhmanoff got a postdoctoral 2-year grant from The Swedish Research Council (VR) to go to Norway (Oslo University) and work with Glenn-Pether Saethre and Thomas F. Hansen.

3. Machteld Verzijden found out, just before Christmas, that she will stay in our lab for 2-3 more years, due a postdoctoral scholarship from the Wenner-Gren Foundations.

4. Former postdoc Shawn Kuchta got a faculty position at Ohio University (Athens, USA), and started up his new lab from the beginning of September 2010. Sophia Engel visited him during November, and I will myself go there for a visit in April 2011.

Needless to say: I am proud to work with such a group of excellent and dedicated scientists as you guys! Although academic life is stressful and we compete (like all other groups) for grants and to get our papers published in good journals, I think we are doing remarkably well, as a lab and as a group. I think this is because we regularly meet and discuss science - in a friendly and cooperative atmosphere. This is the key to sucess - much more than large research grants. I hope we can continue along this succesful path for many years to come.

As for myself, I will now leave for South Africa (well, tomorrow!), and will be back in the last week of January. Until then; enjoy this picture of a Greater Collared Sunbird, photographed in the Eastern Cape Province in South Africa in April this year. My overly ambitious daughter My (who is soon a professional blogger and expert in HTML-programming, by the way), has started up a new photo blog, where she wants us both to upload our photos during the trip to South Africa. You can find it here.

I am not sure I will allocate that much time as my daughter expects me to, as I want to stay away from the internet for a while, when enjoying field work, good wine, birds and wildlife. But keep following this other blog, perhaps I will change my mind :).

Recently we have published two studies based on the isopod system of Asellus aquatics. This species occurs in two ecotypes, which resides in different habitats. As the ecotypes are present in several Swedish lakes, this system has been studied in depth with regard to parallel evolution. Our new articles address differences in mating behavior between the ecotypes. As other crustaceans, A. aquaticus exhibits precopulatory mate guarding where the male captures a female before she is receptive and carries her beneath him until she is ready to mate. This behavior is target for sexual conflict in several isopods as the optimal initiation of pairbonding may differ between the sexes.

One of our articles, published in the latest number of Journal of Evolutionary Biology, deals with differences between the ecotypes in mate guarding duration, but also in differences in female survival and offspring production. Among other things, we found a pattern of parallel evolution in these traits. The other article, published in open access journal PLoS ONE, deals with differences in mating propensity between the ecotypes and how this is affected by demographic factors. Here, we found that the novel ecotype seem to have evolved a plastic behavior as response to sex ratio, in contrast to the ancestral ecotype.

You could find both abstracts below, and both articles are included in Kristina Karlsson Green’s thesis that will be defended on next Friday.

Parallel divergence in mate guarding behaviour following colonization of a novel habitat

K. Karlsson, F. Eroukhmanoff, R. Härdling & E.I. Svensson

Abstract

Ecological factors can have profound effects on mating system and mating behaviour. We investigated the effect of altered ecological conditions, following colonization of a novel habitat, on precopulatory mate guarding in a freshwater isopod (Asellus aquaticus). This isopod occurs in two different ecotypes, which coexist within several different lakes in Sweden but which utilize different habitats. These ecotypes have rapidly (ca. 40 generations) diverged in parallel among lakes in several phenotypic characters, presumably as a response to different predatory pressures. Here, we demonstrate that also mate guarding characteristics have diverged in parallel between the ecotypes in different lakes. This is one of the few studies reporting parallel evolution of mating behaviour. Furthermore, our results also indicate a potential sexual conflict, as the length of mate guarding appears to lower components of female fitness. We discuss how novel environments might have strong and rapid effects on mate guarding dynamics and mating behaviour.

Phenotypic Plasticity in Response to the Social Environment: Effects of Density and Sex Ratio on Mating Behaviour Following Ecotype Divergence

Kristina Karlsson^*, Fabrice Eroukhmanoff, Erik I. Svensson

Abstract

The ability to express phenotypically plastic responses to environmental cues might be adaptive in changing environments. We studied phenotypic plasticity in mating behaviour as a response to population density and adult sex ratio in a freshwater isopod (Asellus aquaticus). A. aquaticus has recently diverged into two distinct ecotypes, inhabiting different lake habitats (reed Phragmites australis and stonewort Chara tomentosa, respectively). In field surveys, we found that these habitats differ markedly in isopod population densities and adult sex ratios. These spatially and temporally demographic differences are likely to affect mating behaviour. We performed behavioural experiments using animals from both the ancestral ecotype (‘‘reed’’ isopods) and from the novel ecotype (‘‘stonewort’’ isopods) population. We found that neither ecotype adjusted their behaviour in response to population density. However, the reed ecotype had a higher intrinsic mating propensity across densities. In contrast to the effects of density, we found ecotype differences in plasticity in response to sex ratio. The stonewort ecotype show pronounced phenotypic plasticity in mating propensity to adult sex ratio, whereas the reed ecotype showed a more canalised behaviour with respect to this demographic factor. We suggest that the lower overall mating propensity and the phenotypic plasticity in response to sex ratio have evolved in the novel stonewort ecotype following invasion of the novel habitat. Plasticity in mating behaviour may in turn have effects on the direction and intensity of sexual selection in the stonewort habitat, which may fuel further ecotype divergence.

An exciting week with the phenotype in the centre of focus: Thesis nailing, lab-meeting (18 November) and dissertation

We have an exciting week in front of us, starting with the nailing of Fabrice Eroukhmanoffs PhD-thesis on Monday 16 October at 15.00. This ceremony will take place at "The Oak" in the bottom floor of the Ecology Building, and drinks will of course be served. Hope to see you all there!

On Wednesday (18 November), we will have our regular lab-meeting in "Darwin" at 10.00. Fabrice will show his Powerpoint-presentation to get some last feedback before the thesis defence on Friday 20 November. We will also discuss a recent paper by David Houle in the journal PNAS, where he suggests that time is now mature for the formation of a new scientific field: "Phenomics". After all the other "-omics"-revolutions in biology (genomics, transcriptomics and proteomics), Houle suggests that we should now return to the most interesting unit of evolution, and what made most of us interested in biology in the first place: The Phenotype. In spite of all the many advances in genomics and other reductionistic fields in molecular biology, our knowledge about how phenotypes evolve, and how they should be measured and quantified is still quite limited. Hopefully, this paper will open up our eyes for a bright future in the field of evolutionary ecology, and give some new idéas for research. You can download the paper here. If the links do not work, contact me or Anna Runemark (anna.runemark@zooekol.lu.se) and try to get a PDF from us instead. By, the way, do we have any "fika-volunteer" on Wednesday morning?

The exciting week does not end on Wednesday, luckily. On Thursday, Fabrice's thesis opponent, Professor Andrew Hendry from McGill University (Canada) will give a research seminar at 13.00 in the "Blue Hall" (note the time: it is one hour earlier than the "official" Thursday seminar which starts at 14.00). Hendry has done a lot of research on rapid evolutionary change in natural populations, gene flow, "eco-evolutionary dynamics" and ecological speciation. Thetitle of Andrew's talk on Thursday 19 November is:

"Ecological speciation (or the lack there-of) in sticklebacks, guppies and Darwin's finches"

Finally, this exciting week with the phenotype in focus will have a grand finale on Friday November 20 in the "Blue Hall" at 10.00, when Fabrice will defend his thesis. I hope as many as possible can and will join in to see Fabrice defending himself against Andrew Hendry, who is known to be a very critical and detail-oriented scientist. Most welcome!

New PhD-thesis in the lab: Fabrice Eroukhmanoff

I am pleased to announce that a new PhD-thesis will now be defended in our group: Fabrice Eroukhmanoff's Magnum Opus "The interplay Between Selection and Constraints on adaptive Divergence and Phenotypic Evolution".

This is the third Ph.D.-student that has finished his/her thesis in our lab, the previous two were Jessica Abbott (2006) and Tom Gosden (2008). You can find an abstract and more informaton about the thesis here. Well done Fabrice!

The thesis will be defended on Friday November 20 in the Blue Hall (Ecology Building). The external opponent will be Professor Andrew Hendry from McGill University Canada, and the thesis committé will consist of Professors Anna Qvarnström (Uppsala University), Karin Rengefors (Limnology, Lund University) and Janne S. Kotiaho (University of Jyväskylä, Finland). The thesis defence is open to everyone, and I encourage you to participate in this exciting event.