Lab meeting on a published and an unpublished paper

Next lab meeting: please note that we will meet at 12:30 in argumentet, so that we can all make it to a meeting of our new 'unit' at 14.00, which will be in the coffee room.

As promised, this time we will discuss the paper by by Tanya Schwander and Olle Leimar, entitled "Genes as leaders and followers in evolution", follow the link to the paper in the earlier blog post about this.

Furthermore, I'd love you input on a paper that I am almost ready to submit, and I'd like you to be my first reviewers. I'll send it around monday morning, if you didn't get it by lunchtime monday, let me know, and I'll send it around again. It is about work that I did during my previous postdoc, on swordtail fish and learning of multimodal cues for species discrimination. Here a picture of the visual cues of the focal species:

Lab meeting cancelled - half time seminars @ zoological museum instead

We're rescheduling, since there is a competing event, namely the half time seminars of 4 PhD students. This will take place at 14.00 at the zoological museum tomorrow.

We will discuss the Schwander & Leimar paper next week, so hold on to your print out if you made it already.

Genes as followers or leaders in evolution?

The lab-meeting the coming week will take place in "Argumentet" (not in "Darwin") at 13.30 on Wednesday, March 23, 2011. We will discuss a TREE-review by Tanya Schwander and Olle Leimar, entitled "Genes as leaders and followers in evolution".  The authors discuss an idéa that has largely been pushed by Mary Jane West-Eberhard that genes are not the most important "actors" in evolution, but are rather followers, and that the environment  plays a more important role than has traditionally been thought, through its effects on the developmental plasticity of organisms. This is a controversial suggestion, and not all evolutionary biologist will necessarily agree. Let's see what the evidence says about this then! Below is more information about the paper.

Genes as leaders and followers in evolution

Tanja Schwander & Olof Leimar

"A major question for the study of phenotypic evolution is whether intra- and interspecific diversity originates directly from genetic variation, or instead, as plastic responses to environmental influences initially, followed later by genetic change. In species with discrete alternative phenotypes, evolutionary sequences can be inferred from transitions between environmental and genetic phenotype control, and from losses of phenotypic alternatives. From the available evidence, sequences appear equally probable to start with genetic polymorphism as with polyphenism, with a possible dominance of one or the other for specific trait types. We argue in this review that to evaluate the prevalence of each route, an investigation of both genetic and environmental cues for phenotype determination in several related rather than in isolated species is required."

Lab-meeting on March 16 2011. New paper on condition-dependent sexual signalling by exiled lab-member Tom Gosden

Next week's lab-meeting we will not read any paper, but instead Machteld Verzijden and myself will give some informal presentations of the talks we will give in a small symposium on insect behaviour and evolution in Stockholm on Thursday, that is arranged by Professor Christer Wiklund in conjunction with a PhD-defence by his student Martin Bergman. Both Machteld and I will of course be happy for any feedback you might have, the day before our official presentations. The title of Machtelds talk is "Ethological speciation mechanisms" and mine is "Ecological vs. non-ecological speciation mechanisms".

If you nevertheless have time and are interested in reading a cool paper, there is one good one that has just been published in Journal of Evolutionary Biology by Tom Gosden and Steve Chenoweth. As you know, Tom is currently in exile in Australia, funded by a Marie Curie "outgoing" postdoc, where he now studies the fascinating and charismatic fruitfly Drosophila serrata, which has recently emerged as somewhat of a model organism in evolutionary quantitative genetics and sexual selection studies. Steve Chenoweth and Mark Blows are leading researchers in this field and have developed sophisticated statistical techniques to estimate breeding values and selection on such breeding values in this species.

The present study tests assumptions behind so-called "genic capture"-model of sexual selection, by looking at the degree of condition-dependence and genetic variation for in condition-dependence among males of Drosophila serrata in relation to a novel food source (yeast). Interestingly, the authors found evidence for condition-dependent sexual signalling, but apparently no genetic variation for condition-dependence, which indicates that it cannot evolve further, at least on this food source. Beware of some heavy maths and statistitics, before you decide to read this paper! Tom will return to Lund in 2012 (same year as Yuma) and bring in fresh new knowledge and skills to our group that he learned in Australia. Below is the abstract of their fascinating paper:

On the evolution of heightened condition dependence of male sexual displays

T. P. GOSDEN & S. F. CHENOWETH

The maintenance of genetic variation in male sexual display traits in the face of strong directional sexual selection from female preferences is an ongoing evolutionary conundrum. Condition dependence and the genic capture hypothesis are often cited as theoretical resolutions to this problem, yet little is known about the ability of condition dependence itself to evolve. We set out to test how a suite of cuticular hydrocarbons (CHCs) used in sexual displays are affected by adult diet and the potential for any condition-dependent response to evolve in a laboratory-adapted population of the Australian fruit fly Drosophila serrata. We performed a dietary manipulation within a half-sib breeding design, raising adult males either with or without access to live yeast, a manipulation that had previously shown strong effects on female fitness. Diet had strong phenotypic effects, with males from the different diets producing different CHC blends. The blend of CHCs under sexual selection showed a degree of elevated condition dependence. Regardless of the heightened sensitivity of favoured CHC blends to diet and the presence of genetic variance for the traits, we were unable to detect any genetic variance in the reaction norms for the male dietary response. Our results suggest that there is limited opportunity for males to evolve further condition dependence in response to yeast availability in this population.

Incoming postdoc Yuma Takahashi from Japan is alive, on Hokaido and is doing well

Given the terrible events in Japan, with the earth quake, Tsunami and threat of nuclear power meltdown, it is of course a relief to hear that incoming postdoc Yuma Takahashi who will join us next year (2012), is alive and he is doing well. Yuma was on a meeting in the north on the island of Hokaido on The Conference of the Ecological Society of Japan when the disaster happened.

Yuma did send me an e-mail with the movie above and assured me that he is doing well. This is a relief, of course, although it is very said with all the human lives that have been lost. Let's keep our fingers crossed that the worst is over and that Yuma can safely come to Lund next year!

Active males, reactive females: stereotypic sex roles in sexual conflict research?

In Animal Behaviour you could now find an article by Kristina Karlsson Green and Josefin Madjidian on the possible use anthropomorphic sex-stereotypes in sexual conflict research. Probably all research on animal behaviour is at the risk of using anthropomorphic descriptions and interpretations but perhaps research dealing with males and females is at special risk. This may be so because sex role stereotypes are among the most common stereotypes in Western society, something which may be difficult to get rid of although we as researchers strive for objectivity. Differences in how the sexes’ are characterised and how research tends to focus on certain aspects of the theory for males and other aspects of the theory for females has been discussed within sexual selection research. Although sexual conflict research also has an extensive focus on the sexes, to our knowledge, our study is the first which addresses how the sexes are conceptualised within this research field. Below you could read the abstract and here you can find the article. You can also find a previous discussion on our blog where the outline of this study first was presented.

Active males, reactive females: stereotypic sex roles in sexual conflict research?

Kristina Karlsson Green and Josefin A. Madjidian

Abstract

Sexual selection research has always been a subject for debate. Much of the criticism has concerned the imposition of conventional sex roles based on an anthropomorphic view of animals imposed by the researcher. This conventional view may have hampered research, for example from acknowledging male mate choice. Sexual conflict theory is a fast-growing research field, which initially stems from sexual selection research. We investigated how the sexes are described in sexual conflict research and what characteristics they are assigned. We assessed these topics with literature studies of (1) the terminology used and (2) what parameters are incorporated in sexual conflict models. We found that males and females are consequently described with different words, which have different connotations regarding activity in the conflict. Furthermore, theoretical models mainly investigate conflict costs for females, although costs for both sexes are necessary for coevolutionary dynamics. We argue that sexual conflict research uses stereotypic characterizations of the sexes, where males are active and females reactive. Thus, previous discussions on the use of anthropomorphic terms in sexual selection seem not to have had any impact on sexual conflict research, which is why the topic of stereotyping the sexes is still of current importance. We suggest that scientific gains can be made by eliminating a sex-stereotyped perspective.

Lab-meeting on inter- and intrasexual conflict

This week's lab-meeting will take place in "Darwin" as usual between 13.30 and 15.00 (Wednesday March 7, 2011). We will discuss and give critical input on two manuscripts that deal with intersexual conflict in plants by Josefin Madjidian and another one intralocus sexual conflict and its effects on sexual dimorphism in birds by Maja Tarka. If you wish to participate and have not yet got the manuscripts to read, send Maja an e-mail (maja.tarka@zooekol.lu.se). After we have discussed these papers, I will briefly discuss the evolutionary stages of sexual dimorphism, illustrating with some data from Calopteryx-demoiselles.

Josefin and Maja have promised to bring "fika". Most welcome!