Showing posts with label phenotypic evolution. Show all posts
Showing posts with label phenotypic evolution. Show all posts

Friday, March 14, 2014

Lab-meeting about phenotypic evolution, the ongoing synthesis and assortative mating







Posted by Erik Svensson

This coming lab-meeting (Tuesday March 18, 10.30), I wanted to discuss a recent general research overview and perspective by evolutionary biologist Stevan J Arnold. It is about the ongoing synthesis in evolutionary biology, but it takes a longer historical perspective. It is the "American Society of Naturalist's Adress", and it is published in the same journal. Hopefully, you will get some feeling for where evolutionary quantitative genetics is today, where it has evolved from, and where it will go in the future. Hopefully, you will also agree that this is still a very dynamic and exciting research approach that will continue to provide many new insights in the genomic and postgenomic era, as it is a synthetic approach that adresses questions that cannot and will never be answered by molecular approaches alone.

You will find the title, the abstract and a link to the article below. Related to this article, I will also spend a few minutes showing some simulation results of what disruptive selection gradients are useful for, and how they can be used to say something about the future.

Phenotypic Evolution: The Ongoing Synthesis

 

I explore the proposition that evolutionary biology is currently in the midst of its greatest period of synthesis. This period, which I call the Ongoing Synthesis, began in 1963 and continues at the present time. I use analysis of citations, conduct, and content to compare the Ongoing Synthesis to widely recognized periods of synthesis in the nineteenth and twentieth centuries. To compare content, I focus on phenotypic evolution and compare current efforts with George Gaylord Simpson’s struggle to understand evolution in deep geological time. The essence of current effort is captured by the question, What is the best model for phenotypic evolution? Although many investigators are actively engaged in answering this question, I single out two examples of my own collaborative work for emphasis here. These two studies share three important characteristics: diagnosis of evolutionary pattern using massive data sets, validation of model parameter values using compilations of estimates (e.g., heritability, stabilizing selection, distance to an intermediate optimum), and identification of evolutionary process using alternative models of stochastic evolution. Our primary findings (discovery of the blunderbuss pattern and the result that rare bursts of evolution carry lineages out of established adaptive zones) compare favorably with important insights from the Modern Synthesis.

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!

Monday, November 2, 2009

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.