Friday, March 27, 2009

Lab-meeting on Wednesday April 1: Flight of dragonflies!


















In light of the recent and very succesful CAnMove meeting on the interface of physics and biology, it seems appropriate to have next lab meeting focus on the interface of physics and odonatology. In particular, flight.

We've chosen two chapters out of the book Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research (edited by Cordoba-Aguilar, 2008). Both chapters are at the end of the book, and are short:

Chapter 19: Dragonfly flight performance: a model system for biomechanics, physiological genetics, and animal competitive behavior (Marden)

Chapter 20: Evolution, diversification, and mechanics of dragonfly wings (Wooton and Newman).

If you do not own this book, both chapters can be found in Shawn Kuctha's mailbox (2nd floor, Ecology Building), where you can copy them. Alternatively, you could contact him directly (shawn.kuchta@zooekol.lu.se).

Monday, March 23, 2009

Paper for this week's lab-meeting: worms!

No one has picked a paper yet, so I thought I'd jump in. My first thought was to pick something from the new book, Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research. But next week will be a busy week, and I was instead turned on to a paper that is rather fun, and is PC in that it is open source.

The paper is on "worm grunting", and is a very cool example on how humans take advantage of an antipredatory response in worms (such a think is not necessarily limited to humans). It also appears at first glance to be a good example of the value of multiple working hypotheses (something we all need to remember). The paper can be downloaded here.


Enjoy,
Shawn

Sunday, March 22, 2009

Last week’s paper “What, if anything, is sympatric speciation?” and a critical evaluation of the 4 criteria proposed by Coyne and Orr (2004)

Hello everybody,

Last week, we discussed a paper by Fitzpatrick et al. (2008) with the title ‘What, if anything, is sympatric speciation?’ Most of us felt that the points put forward were a good contribution to the ‘speciation debate’ and agreed that a general shift from the pattern orientated way of classifying speciation (allopatry vs sympatry) towards a more process based system would be fruitful.

Today, I would like to add some thoughts about the four criteria that were proposed by Coyne and Orr (2004), as we did not have time to discuss this during the meeting. I will do this by adding a little marine perspective to it. This is because a) roughly ¾ of the earth is covered by water, and b) approximately half of the vertebrate species are made up of fish (including jawless, cartilaginous and bony fish). I obviously had to deal with these criteria a lot during my PhD, so here comes what I think:

The four criteria that need to be met to corroborate that a species has evolved under sympatry:
1) a sympatric distribution of the most closely related sister-species;
2) genetic evidence for reproductive isolation;
3) lineage monophyly; and
4) an ecological setting in which historical allopatric differentiation in a biogeographical context is very unlikely.


Recent work suggests that the first criterion, 'the sympatric distribution of the most closely related sister-species', may not always be the case. For example, Doebeli and Dieckmann (2003) have shown that when ecological interactions actively drive diversification, then species that diverge in sympatry may subsequently become allopatric (i.e. to reduce competition). In light of this, the sympatric distribution of sister-species may not always be a reliable indicator of historical sympatry (or vice versa).

The fourth criterion is also problematic as it states that there must be an ecological setting in which allopatric differentiation is very unlikely e.g. remote oceanic islands, hosts for parasites or small crater lakes (Coyne and Orr 2004). These are all very geographically constrained and homogenous habitats and do not apply to most species, and in particular the vast majority of marine species. Why should sympatric speciation be any less likely in heterogeneous systems? Recent theoretical research has suggested that it is not (for details see Doebeli and Dieckmann 2004 and references therein). Recent theoretical models of sympatric speciation have shown that speciation may crucially depend on spatial structure. In a single and homogenous population, stochastic fluctuations will only be sufficiently large when the population size is small. Yet, with spatial structure, fluctuations can be considerable, even in a large population. Therefore, a small spatial component may greatly enlarge the potential for speciation, as local adaptation along an environmental gradient has the potential to increase the strength of frequency-dependent selection (Doebeli and Dieckmann 2003; Doebeli and Dieckmann 2004). Furthermore, inferring the historical patterns of speciation events (sensu Barraclough and Vogler 2000) is problematic because geographic distributions change over time (Losos and Glor 2003). Thus, it becomes clear that the current distribution of a species is not necessarily a reliable guide to its historical geographical range, therefore, it is crucial to acknowledge that geographical ranges shift and that geographical signal decays over time.

Another general criticism of the Coyne and Orr (2004) criteria is that there is an underlying burden of proof that requires sympatric models to exclude historical geographic barriers to gene flow. Conversely, no studies of allopatric speciation to date have excluded the possibility of historical sympatric distributions (Berlocher 1998). Researchers seem to be expected to treat allopatric speciation as the null model, even though several empirical studies have convincingly demonstrated sympatric speciation. Dieckmann et al. (2004) proposed that the time has come to do away with the notion of allopatric speciation as the null model, a notion that prevails partly because of the deceptive simplicity of allopatric scenarios. Once the bias towards detecting allopatric speciation in empirical data is removed, the data may actually suggest speciation without complete barriers to gene flow is the more likely explanation of many speciation events. This dichotomy can partly explain why evidence for sympatric speciation in heterogeneous environments is sparse. Given that most species inhabit heterogeneous environments, case studies of speciation events on small islands or lakes tell us little about the processes that act on species in spatially variable environments.

Ruling out that ancestral species may have once been allopatric is particularly problematic in marine fish species, as it is usually impossible to exclude the possibility that sympatric species were historically allopatric (Sponer and Roy 2002). Furthermore, speciation in the face of gene flow has been largely discounted in marine fishes because most species have a planktonic larval phase with the potential to disperse widely and generate genetic homogeneity over large spatial scales (Knowlton 1993; Palumbi 1994). However, there is increasing evidence that larvae do not always disperse long distances and some return to their natal reefs (Jones et al. 1999; Swearer et al. 1999; Swearer et al. 2002). Furthermore, habitat selection at settlement (reviewed in: Montgomery et al. 2001) and assortative mating (e.g. McMillan et al. 1999) can produce reproductive isolation at very fine spatial scales. This evidence suggests that a pelagic larval phase need not preclude the formation of fine-scale genetic structure because behaviour can override the potential for genetic mixing (Taylor and Hellberg 2003).

Before this post gets too long I would like to point to the excellent paper by Bolnick and Fitzpatrick (2007 ) in which they address in more detail the points 2 and 3.
I am sure some of you have some thoughts on the criteria proposed by Coyne and Orr as well, so please comment on this post.

Cheers, Maren

Friday, March 20, 2009

Criticism of Richard Dawkins and the new atheist movement
























As evolutionary biologists, we should know the struggle of biologist Richard Dawkins and philosopher Daniel Dennett in defense of evolutionary theory against creationists and religious fanatics. Dawkins and Dennett have also recently been joined by non-biologists, like former leftist writer and critic Cristopher Hitchens, in a struggle not only against creationism per se, but in a broader struggle against religion in general.

All these authors have published books recently which are very critical of organized religion, the most well-known being Dawkins bestseller "The God Delusion". These strong personalities have built up something of a movement which is sometimes called "The New Atheism", with provocative advertisements on buses in England with the message: "God does probably not exist".

What to think about this new movement? From my perspective, I have mixed feelings. On the one hand, I am an atheist myself, who would like to see a world will less power for organized religion. On the other side, I dislike the preaching style of both Dawkins, Dennett and Hitchens and think that they might be doing more bad than good in their self-contentious and aggressive atheistic preaching crusade. Their campaign might thus backfire, and push moderate religious groups into allies with religious fanatics. That would be very unfortunate, which is one reason why I am not very enthusiastic about Dawkins recent book and his ongoing atheist campaign.

My mixed feelings are shared by Julian Baggini in this interesting opinion piece, where he argues that the new atheism is destructive. I am also a bit frustrated that a legitimate defence of evolutionary theory (necessary in my opinion), might be "drowned" and confused in campaign for atheism, which is not a scientific movement.

Lab-meeting next week?

This is a suggestion to anyone in the lab to think of a possible article for next week's lab-meeting on Wednesday. I will myself be busy planning the "Biology-Physics Interface"-workshop on Wednesday afternoon, so I will not have time to suggest an article. But I would strongly encourage "somebody" to suggest an article, and post the information here, on this blogg. Ideally, you should both write a few sentences (5-10) in a bloggpost and provide a link to the article so that it can be downloaded by members of our laboratory. So please feel free to suggest something for Wednesday next week!

"The Biology-Physics Interface": symposium in Lund Wednesday 25 March























We had some excellent discussions with our visiting Finnish guests, and I was hoping that some of you could soon write some bloggpost(-s), where you summarise your thoughts and impressions about Lamarck, species concepts and/or sympatric speciation. Shawn or Maren perhaps? Also, I think we would be interested in a bloggpost from Tina and Josefin, who had a separate discussion about sexual selection/sexual conflict. Please share with the rest of us some of your thoughts and idéas.

For the next week, I would again like to remind about the workshop on "The Biology-Physics Interface", that I am organizing here in Lund together with limnologist Lars-Anders Hansson. This a so-called CAnMOVE-event - "Centre for Animal Movement" - our new "Linnaeus-programme" about animal movement research. I hope that you all can participate and listen to the talks next Wednesday between 13.00 and 18.30 in the "Red Room" (Ecology Building). Below, I have pasted in the programme for the workshop:


13.00-13.15: Welcome! Introductory words - Erik Svensson

13.15-13.30: Presentation of CAnMove - Susanne Åkesson

13.30-14.15: Remote sensing of animal movement – unconventional laser radar possibilities
Sune Svanberg

14.15-14.45: Dragonflies and damselflies as bioinspirators - Erik Svensson

14.45-15.15: Seeing animal flight through the side-wall of a wind tunnel - Anders Hedenström

15.15-15.45: COFFEE BREAK

15.45-16.15: Nanotechnology in biology - Waldemar Hällström

16.15-16.45: Optical Spectroscopy in Animal Appearance and Perception -
Mikkel Brydegaard


16.45-17.15: Magnetic resonance imaging: Morphology and function - Ronnie Wirestam

17-15-17.45: Individual labeling of small animals (Daphnia) - Bengt Danielsson

17.45-18.30: Plenary Discussion: How can methods from physics be of use in biology?
Moderator: Lars-Anders Hansson

Tuesday, March 17, 2009

1979: A great year for evolutionary biology!

2009 celebrates the 150th anniversary of “The Origin of Species”, we all know that too well. But are there any other memorable 1xx9 year for evolutionary biology? In 1979, 120 years after the “origin of species”, two major papers were published and revisited the concept of constraint in evolutionary biology.

On one side, the “romantic” view of constraints, with Lewontin and Gould who wrote a paper entitled "The Spandrels of San Marco and the Panglossian Paradigm" (Proceedings) which introduced the architectural term spandrel into evolutionary biology. A spandrel is the space that exists between arches. When visiting Venice, Gould noted that the spandrels of the San Marco cathedral, while quite beautiful, were not planned, but rather resulted from the arches the architects deliberately designed. Gould and Lewontin thus defined the word "spandrel" in evolutionary biology as a coincidental character, which does not directly result from selection but from contingency, although which may eventually increase fitness. This would later on lead Gould to further investigate the issue of exaptation and preadaptation, which had been introduced already in 1859 by Darwin. So far this paper has been cited 2536 times according to Google scholar, and remains one of the most studied papers in evolutionary biology by undergraduate students, at least in France.

On the other side, the more “pragmatic” view, with Lande, who wrote another very much cited paper (843 times), and in certain fields of evolutionary biology, even more influential: “Quantitative genetic analysis of multivariate evolution, applied to brain: body size allometry” (Evolution). This was the first study to really assess the constraining effects of genetic covariation between traits. By using data from selection experiments on brain and body size, Lande hypothesized that in certain mammalian groups such as primates, reduced covariation between these two characters might have enabled encephalization through direct selection. However, the real reason why this paper has had a profound effect on evolutionary biology is because it has (re-)introduced multivariate quantitative genetics methods to study phenotypic evolution. After this, studies on the constraining role of the genetic variance-covariance matrix during phenotypic evolution have flourished.

The reason why I wrote this post is because I think it might be interesting to discuss these two classic papers with the aim of addressing the influence they have had so far on our own work, if any, or on the current agenda of evolutionary biology. However, I am quite tied up right now with my parental leave, so it won’t be any time soon for me, but maybe we could plan something in April for one of our Wednesday meetings. In the mean time, you guys are free to react on that and maybe to propose other key papers published in 1979 that I might have forgotten.

Fabrice Eroukhmanoff.

Monday, March 16, 2009

Visit by Finnish colleagues this week

As you hopefully already know, Drs. Katja Tynkkynen and Janne Kotiaho from University of Jyväskylä in Finland will visit our department and our research group this week. They will arrive tomorrow (Tuesday), and will participate in our lab-meeting on Wednesday morning (10.15). Maren will provide some "fika".

We will discuss two papers suggested by Janne, that have already been sent out to you. Please contact me or anyone else in the group if you have not got these papers, so that you are prepared for Wednesday morning. Both papers deal with species concepts and speciation, one with Lamarck's species concept, the other with definitions of sympatric speciation.

The title of the papers for the seminar are:

Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck

On classification and evolution


Philosophie zoologique, ou exposition des considérations
relatives à l'histoire naturelle des animaux.

(Zoological Philosophy. An Exposition with
Regard to the Natural History of Animals)

by J.B. Lamarck
1809
Translated by Hugh Elliot

Macmillan, London 1914
Reprinted by University of Chicago Press, 1984


And:


Fitzpatrick et al. 2008. What, if anything is sympatric speciation? 2008.
J. Evol. Biol. 21:1452-1459.



After the lab-meeting, I will bring Janne for a lunch on Wednesday together with Susanne Åkesson, Anders Brodin, Anders Hedenström and Dennis Hasselquist. We will plan the International Behavioural Ecology Congress (ISBE) that will take place in Lund 2012, and we would like to get some feedback and advices from Janne about his experiences when he arranged the ISBE-meeting in Jyväskylä a few years ago. I hope the rest of you can take care of Katja during Wednesday lunch. The afternoon will be set aside for scientific discussions in the "Darwin"-room, where Katja will present some of her work.

On Thursday (19/3), Janne will present a talk about the history of sexual selection, that will take place in the "Blue Hall" (bottom floor in the Ecology Building) at 14.00. The title of this talk is:

"The past and present of the theory of sexual selection through mate choice"

Janne has promised to present a historical overview about the intellectual roots of the idéa of sexual selection through female choice, and the (possible) role of the feminist movement in affecting its scientific acceptance in the early 1980'ties, more than hundred years after it was originally developed by Charles Darwin.

This is likely to be a fun, and perhaps also controversial talk, so do not miss it! Janne has promised to "discuss some of the slightly less pleasent aspects of the current scientific enterprise through some examples stemming from sexual selection.". We are indeed looking forward to this.

Saturday, March 14, 2009

First bloggpost - Welcome!



















Dear All,

Welcome to this blogg, and the first bloggpost - ever!

Above you see a picture of one of Sweden's latest arrivals in its damselfly fauna: The Small Red-eyed damselfly (Erythromma viridulum). The males in this species have characteristic red eyes, which contrasts markedly to the otherwise blue colouration of the body. The picture was taken by me in late summer (July) 2008 at "Råbydammen" between Dalby and Lund.

This enigmatic damselfly species has exploded in Skåne and is one of the most common damselfly species in newly created ponds, after only a few years. It is only one of several examples of southernly odonate species that are currently expanding northwards in Europe - presumably due to climate change.

And now over to something different:

Blogs and the bloggosphere is here to come - accept it and do not fight back. This is the future, we better adjust to it as scientists and learn the new tools of communication. It is worth putting a little bit extra effort to do this - because it will benefit you in your future career.

I hope we will all contribute to make this blogg truly interactive, in which all contribute by commenting and writing posts (for those who have gotten permission from me to do so). Only by keeping this blogg live and active will it be interesting and useful. You should also consider to post interesting links about research news or scientific papers that are likely to be of interest, not only to our research laboratory, but also to a broad audience of ecologists and evolutionary biologists. Science politics and science policy news - from Sweden, the US or other parts of the world is of course also of interest here. As will be news about our field work or scientific meetings that we have attended and where you might want to share your thoughts.

But the primary function of this blogg will be for our weekly lab-meetings. I expect all who propose papers to write a shorter or longer bloggpost (a minimum of five sentences, and longer if you wish), where you explain why you chose this paper and why you thought it might be important. You should also add a link to the article so that other lab-members could download the paper and prepare for the meeting. Afterwards, if you or somebody else in the lab has some thought(-s) about the paper or new idéas that you might want to share with the rest of us: please post it here, or add a comment! In this way, we can document the scientific and intellectual processes in our laboratory.

So: get going, log on and add your own bloggposts! It is not difficult and you are all intelligent people. I know, because I am your advisor! If an old dinosaur like me can blogg - you can too! Why wait? How many hours will it take until the next blogg post will appear by anyone from my laboratory? And when will the first comment appear on this blogg? Soon, I hope...

Looking forward to many interesting posts by you soon!