Saturday, February 18, 2012

New blog name and a few words about the past and the future

Some of you might already have noted this, but the blog has recently changed its name from the more person-oriented "Erik Svensson Research Laboratory", to the more general name "Experimental Evolution, Ecology and Behaviour" (Acronym: EXEB). This is more than cosmetics and simply a changed name: it reflects a significant change that had as its starting point over a decade ago, in 2000, when I returned from my postdoc in the US.

By that time, our department was (and still largely is), very dominated by bird behavioural ecology and two large research groups: Molecular Ecology and Bird Migration Ecology. It was therefore a bit odd to try to start up something in between these two large groups, that was neither, and in this case an evolutionary and ecological research programme focussed on field studies on insects and with a strong connection to quantitative genetics and selection approaches. Moreover, at that time (unlike today), odonates were still considered to be quite odd study organisms, both in Lund and elsewhere. It was quite lonely, at times, to strive to cut out an independent niche in a department so strongly focussed on birds and behavioural ecology, and it was tempting several times to give up, and just follow the crowd along some easier path.

Luckily, I got several excellent PhD-students, who were all succesful in terms of their theses, defended, got postdocs and went abroad to learn new things: Jessica Abbott in 2006, Tom Gosden in 2008, Fabrice Eroukhanoff in 2009 and Kristina Karlsson in 2010. Of these former PhD-students, Jessica recently obtained a "Junior Project Grant" from "Vetenskapsrådet" last year, and as you know she has now re-established herself in Lund and in our research environment. She is hopefully not the last of my current and former PhD-students/postdocs who will be able to establish herself as an independent PI, but only the future will tell this, of course. This spring several of you will apply from VR, and later this year, Tom Gosden will return to Lund from Australia on a one-year postdoc (Marie Curie). Any new PhD-students entering this group will have an idéal situation in the form of several postdoctoral mentors, good role models and senior scientists.  

Given these happy and exciting developments, I feel that the goal I did put up more than a decade ago, i. e. to build up a new evolutionary oriented research group in Lund focussing on insects/invertebrates, has largely been achieved. As there is now more than one senior scientist and PI,  it is time for me to transform this group in to more of a collective enterprise, and less of a one-man show. This has already started to happen,  naturally, as lab-meetings were obviously running when I was recently away in South Africa. This is great, and exactly how I want it to be. A research group cannot stand and fall with a single person, it has to be a collective effort.

Time is therefore mature to change the name of both the blog and the research group. These new changes will soon be seen also at the the department's website. I strongly feel that it is important to have a group of people who regularly meet, as several brains work synergistically, and intellectual lab-meetings of the kind we have had over the years should be the last thing to prioritize down, even if time is always limited. As for myself, I will now try to cut down on the number of projects, focus more on my own research and hopefully share some of the administrative burden and advising activities with Jessica and those others of you who might also hopefully soon enter as new PI:s.

A few more words about the new name of the blog, which I and Jessica have discussed before deciding on  EXEB. "Experimental Evolution", i. e. the first two words, signify the important fact that Jessica brings with her an entirely new research approach to Lund and our research group, while at the same time we keep our strong focus on ecology and behaviour.

Some might argue that there are other groups in our department working with these topics too, and that our research group is therefore obsolete or unnecessary. Perhaps we should simply dissolve it, and happily integrate ourselves with other similar groups like MEEL, The PEG ("theoretical ecology") or "Bird Migration Ecology"?. Well,  I do not think so, otherwise I would of course have shut down this blog a long time ago. Personally, I think we represent a significant and different research current than these other groups, without denying that they also do good work.

There is clearly room for a research group that is both integrative (i. e. combines molecular, experimental and field approaches) and theoretically oriented (although not a pure theory group), and which is firmly rooted in population and evolutionary quantitative genetics. That is who we are and what we are good at, I think. And we also have a certain responsibility to represent this particular research tradition in Lund, rather than trying to copy others and become too similar to other research groups.

Finally: Goodbye "Erik Svensson Research Laboratory" and long live EXEB!

New Drossie paper, multivariate genetic constraints on sexual dimorphism

A quick post from down under highlighting a new paper that has just gone "online early" at Evolution. It contains work I have been doing with Steve Chenoweth on the Australian vinegar fly, Drosophila serrata (see picture above). In the paper we attempt to quantify the degree of constraint imposed on sexually homologous traits by the between-sex covariance matrix, B, first introduced in a seminal paper by Lande in 1980. For those not familiar with quantitative genetics it is a little heavy in places, but I hope that you will all find it relatively easy to read and enjoyable none-the-less. For any of you who can't get to it behind the paywall, please feel free to e-mail me and I'll be happy to send you a copy.

Title and abstract:



The extent to which sexual dimorphism can evolve within a population depends on an interaction between sexually divergent selection and constraints imposed by a genetic architecture that is shared between males and females. The degree of constraint within a population is normally inferred from the intersexual genetic correlation, rmf. However, such bivariate correlations ignore the potential constraining effect of genetic covariances between other sexually coexpressed traits. Using the fruit fly Drosophila serrata, a species that exhibits mutual mate preference for blends of homologous contact pheromones, we tested the impact of between-sex between-trait genetic covariances using an extended version of the genetic variance–covariance matrix, G, that includes Lande's (1980) between-sex covariance matrix, B. We find that including B greatly reduces the degree to which male and female traits are predicted to diverge in the face of divergent phenotypic selection. However, the degree to which B alters the response to selection differs between the sexes. The overall rate of male trait evolution is predicted to decline, but its direction remains relatively unchanged, whereas the opposite is found for females. We emphasize the importance of considering the B-matrix in microevolutionary studies of constraint on the evolution of sexual dimorphism.

Monday, February 13, 2012

On "Evolutionary rescue", climate change and evolution of range limits

This week the lab-meeting will focus on  "Evolutionary rescue", which was a topic of a recent scientific conference involving several leading evolutionary biologists and ecologists in France, including leading population geneticist Mark Kirkpatrick who gave a talk entitled: "The evolution of a species’ range by beneficial mutations"

The organisers of this interesting conference has been kind enough to put up videos on the internet of Mark's talk, which you can find here, as well as two other interesting talks by contributors. This is an excellent way of making it possible for others, like us, who could not take part in this meeting, and also a very environmentally-friendly way of spreading scientific information without necessarily travelling to every meeting you wish to attend.

I suggest that we meet the usual time (13.30 on Wednesday April 15 in "Argumentet") to listen to Mark's talk, and (if we have time), to one or two of the other talks. Thus, there is no need to read any paper before this lab-meeting, just come sharp and alert and be willing to discuss! Hopefully, we can arrange with Machteld's computer to be linked to the Powerpoint-projector so we can see the talk on a large screen. 

 

Monday, February 6, 2012

new time for next gathering

The usual time (13.00) clashes with the course on animal handling that some of us are taking (including me). Therefore, it's moved forward to 12.00 (in Argumenthet) and we'll make it a lunch meeting.
Hope this works for everyone?

Friday, February 3, 2012

The life of a researcher

Jessica and I have been talking about getting together and talk a
bout how to deal with the demands, uncertainties, but also the myriad of possibilities and exciting pro's that come with our choice of career. How to keep a handle on it all, and feel confident making choices, either in career directions, but also in time-allocation issues in everyday work life. Though these issues may change somewhat along the way, we thought it'd be good for all of us to discuss this with people that are at various stages of their career, share experiences and considerations.

So, instead of discussing a particular scientific paper this coming wednesday, let's get together and share our experiences and insights and learn from each other!

I think we can have this meeting without reading material, but if anyone has a good suggestion, please post!

Wednesday, 13.00, Argumenthet.

Monday, January 23, 2012

sexual dimorphism

In the absence of them lucky bastards pouncing around in the Cape fijnbos or something, spotting zebras, sunbirds and eating fresh mango and grapes for lunch (no, not envious at all, clearly), we will huddle up in Argumenthet in this cold weather and discuss some fine science.

This week's paper is:

Jeffrey C. Oliver and Antónia Monteiro

Proc. R. Soc. B (2011) 278, 1981–1988 doi:10.1098/rspb.2010.2220



Wednesday 13.00 (the usual). Fika anyone?


The abstract:

The processes governing the evolution of sexual dimorphism provided a foundation for sexual selection theory. Two alternative processes, originally proposed by Darwin and Wallace, differ primarily in the timing of events creating the dimorphism. In the process advocated by Darwin, a novel ornament arises in a single sex, with no temporal separation in the origin and sex-limitation of the novel trait. By contrast, Wallace proposed a process where novel ornaments appear simultaneously in both sexes, but are then converted into sex-limited expression by natural selection acting against showy coloration in one sex. Here, we investigate these alternative modes of sexual dimorphism evolution in a phylogenetic framework and demonstrate that both processes contribute to dimorphic wing patterns in the butterfly genera Bicyclus and Junonia. In some lineages, eyespots and bands arise in a single sex, whereas in other lineages they appear in both sexes but are then lost in one of the sexes. In addition, lineages display- ing sexual dimorphism were more likely to become sexually monomorphic than they were to remain dimorphic. This derived monomorphism was either owing to a loss of the ornament (‘drab monomorph- ism’) or owing to a gain of the same ornament by the opposite sex (‘mutual ornamentation’). Our results demonstrate the necessity of a plurality in theories explaining the evolution of sexual dimorphism within and across taxa. The origins and evolutionary fate of sexual dimorphism are probably influenced by underlying genetic architecture responsible for sex-limited expression and the degree of intralocus sexual conflict. Future comparative and developmental work on sexual dimorphism within and among taxa will provide a better understanding of the biases and constraints governing the evolution of animal sexual dimorphism.

Monday, January 16, 2012

Lab-meeting on sexual selection, sexual conflict and cross-sexual transfer

It is time for a last lab-meeting before I go to South Africa for field work for three weeks. After a discussion with Jessica Abbott, I thought it would be fun to diskuss a recent conceptual paper by Russel Bonduryansky entitled: "Sexual Selection and Conflict as Engines of Ecological Diversification". You will find a copy of this paper here, and the Abstract below.

Due to other committments, I suggest we meet at 13.30,  not 13.00, in "Argumentet" on Wednesday January 18 2012.Looking forward to see you all and an interesting discussion.



Abstract: Ecological diversification presents an enduring puzzle: how do novel ecological strategies evolve in organisms that are already adapted to their ecological niche? Most attempts to answer this question posit a primary role for genetic drift, which could carry populations through or around fitness "valleys" representing maladaptive intermediate phenotypes between alternative niches. Sexual selection and conflict are thought to play an ancillary role by initiating reproductive isolation and thereby facilitating divergence in ecological traits through genetic drift or local adaptation. Here, I synthesize theory and evidence suggesting that sexual selection and conflict could play a more central role in the evolution and diversification of ecological strategies through the co-optation of sexual traits for viability-related functions. This hypothesis rests on three main premises, all of which are supported by theory and consistent with the available evidence. First, sexual selection and conflict often act at cross-purposes to viability selection, thereby displacing populations from the local viability optimum. Second, sexual traits can serve as preadaptations for novel viability-related functions. Third, ancestrally sex-limited sexual traits can be transferred between sexes. Consequently, by allowing populations to explore a broad phenotypic space around the current viability optimum, sexual selection and conflict could act as powerful drivers of ecological adaptation and diversification.