Lab-meeting: between-sex covariance for dummies explained by Tom Gosden

Posted by Erik Svensson

Next week, EXEB-member Tom Gosden will give a practice talk of his forthcoming Friday seminar about between-sex covariance and genetic constraints on the evolution of sexual dimorphism.

As many of you already know, Tom is a former PhD-student in our laboratory, and is currently visiting postdoc, until he will return to Brisbane in Australia where he will commence a Junior Research position.

Tom's informal talk will be about fruitflies (Drosophila) and how to understand, interpret and estimate between-sex genetic covariance, and Tom has promised to explain it also to non-experts. Note that the lab-meeting time has been changed to afternoon from morning and to another locality on 3rd floor. For those of you who want to get a deeper idéa what Tom's research is about, here is a link to a recent article he published in Evolution.

When: Tuesday March 4 2014, 14.00-15.30
Where: Seminar room "Communis", 3rd floor (Ecology Building)

 Everybody should be most welcome!

THE B-MATRIX HARBORS SIGNIFICANT AND SEX-SPECIFIC CONSTRAINTS ON THE EVOLUTION OF MULTICHARACTER SEXUAL DIMORPHISM 

Thomas P. Gosden, Krishna-Lila Shastri, Paolo Innocenti, Stephen F. Chenoweth

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.

Lab-meeting about intralocus sexual conflict and seminar by Jessica Abbott

This week's lab-meeting has been moved to Thursday morning (10.00-12.00) and to the seminar room "Fagus" (third floor above "Darwin"), due to the seminar by outside visitor and former lab-member Jessica Abbott in the same day, in the afternoon (14.00, "Blue Hall").

The theme of Jessica's talk will be intralocus sexual conflict and genetic constraints, and that will also be the theme of our lab-meeting. I was thinking that we should discuss a recent review by Jessica in Proc. R. Soc. Lond. B. about how one can study intralocus sexual conflict in hermaphroditic animals. Hopefully, Jessica will arrive in time to comment on this paper as well, her expected arrival time to the Department is about 11.00.

Before we discuss Jessica's interesting review-paper, we will discuss a manuscript that I and Fabrice Eroukhmanoff have written about population variation in intersexual genetic correlations and sexual dimorphism in aquatic isopods (Asellus aquaticus). We have worked on this manuscript for quite a while and we would be interested in getting some input. The results have clear links to the research topic and interests by Jessica. We will send you out this manuscript in a separate e-mail, hopefully today (Monday). Send me an e-mail if you do not get it (erik.svensson@zooekol.lu.se).

After our lab-meeting in "Fagus", there will be opportunity to go for lunch with Jessica, and at 14.00 her seminar starts in the "Blue Hall" in the Ecology Building, entitled:


"Using sex-limited evolution to detect evolutionary constraints"

You can read more about Jessica's research here, and here you can find a list of past and more recent publications.