Friday, February 27, 2015

The social essence of sexual selection

Posted by Beatriz Willink


For next Tuesday we will read a paper on the evolutionary neurobiology of male–female interactions, which argues for looking at sexual selection in a social context. I hope it inspires an interesting discussion.

When: 10:30 March 3, 2015

Where: Argumentet, Ekologihuset 2nd floor



Abstract: Darwinian sexual selection can now be seen in the broader context of social selection, or social competitionfor resources (under sexual selection, mates or fertilization success). The social-interaction aspects of sexually selected traits give them special evolutionary properties of interest for neurobiological studies of stimulus–response systems because they can account for highly complex systems with little information content other than stimulatory effectiveness per se. But these special properties have a long history ofbeing forgotten when other factors dominate the analysis of male–female interactions, such as the mistakenbelief that differential responsiveness to signals produced by competing rivals (“female choice”)requires an esthetic sense; that species recognition explains all species-specific sexual signals; and, morerecently, that successful signals must reflect good survival genes; or that male–female conflict involvesfemale resistance rather than stimulus evaluation. A “conflict paradox” results when male–female conflict is seen as driven by natural selection, whose costs should often move the hypothesized “sexually antagonistic co-evolution” of sensory-response systems toward the powerful domain of sexually synergistic co-evolution under sexual selection. Special properties of sexual selection apply to other forms ofsocial competition as well, showing the wisdom of Darwin’s setting it apart from natural selection as anexplanation of many otherwise puzzling and extreme traits.

Thursday, February 19, 2015

Sexual selection and sexual conflict in plants

Posted by Anna Nordén 

SEM image of pollen grains.
For the next lab meeting (Feb 24th) I thought we could focus on plants for a change. I suggest that we discuss a new review article by Åsa Lankinen and former lab member Kristina Karlsson Green, about sexual selection and sexual conflict in plants. Theories of sexual selection and sexual conflict have been extensively studied in animals (especially insects), and the authors wish to incorporate some of these theories to plant research. In the end, they also suggest three plant research fields where these theories could be helpful. I hope that we will all learn something new and broaden our perspectives a bit!

Time and place as usual (10:30 in Argumentet, ekologihuset 2nd floor). I will provide fika.
 

Authors: Åsa Lankinen and Kristina Karlsson Green

Friday, February 13, 2015

Lab-meeting about genomics and phenomics





Posted by Erik Svensson

This forthcoming Tuesday, we will discuss two papers, one chosen by Katie and one by me, which deal with genomics and phenomics, respectively. The latter term is still a bit unfamiliar to many, but "phenomics" is most likely a new word you would like to know, as it will hopefully become the new "buzzword" in the future and in the postgenomic era. Hopefully, we can have a general discussion of principal interest how to connect the more traditional field of genomics and the emerging field of phenomics.

You will find Abstracts and links to the two papers below. Time and place as usual:

When: Tuesday, February 18 2015


Where: "Argumentet", 2nd floor, Ecology Building



Sequencing pools of individuals - mining genome-wide polymorphism data without big funding

The analysis of polymorphism data is becoming increasingly important as a complementary tool to classical genetic analyses. Nevertheless, despite plunging sequencing costs, genomic sequencing of individuals at the population scale is still restricted to a few model species. Whole-genome sequencing of pools of individuals (Pool-seq) provides a cost-effective alternative to sequencing individuals separately. With the availability of custom-tailored software tools, Pool-seq is being increasingly used for population genomic research on both model and non-model organisms. In this Review, we not only demonstrate the breadth of questions that are being addressed by Pool-seq but also discuss its limitations and provide guidelines for users. 





Sunday, February 1, 2015

Labmeeting about neotropical biology in Guyana and genomics in the Czech Republic










Posted by Erik Svensson (all photographs above taken i Guyana in January 2015)

On lab-meeting this coming week, we were thinking that we shall not discuss any paper, but rather those of us who have been away (me, Beatriz and Katie) should talk a little bit about our expeditions to Guyana i South America and the Czech Republic, respectively. 

I hope to be able to process some of my many nature photographs from mine and Beatriz odonate research expedition, so that I can show them at the lab-meeting. Above is a slight teaser. Hopefully, I will have more on Tuesday. And Katie will tell us about what she learned in the genomics workshop and thoughts about the future and what she can use her new skills to do.

Any fika volunteer?

Time: Tuesday, February 3, at 10.30
Location: "Argumentet", 2nd floor, Ecology Building

Monday, January 26, 2015

Cope's rule and the evolution of body size in Pinnipedimorpha (Mammalia: Carnivora)


For Tuesday, We are reading about Seal-body-size evolution. 


Cope's rule describes the evolutionary trend in animal lineages to Increase in body size overtime. In this study, we tested the validity of Cope's rule for a Marine Mammal clade, the Pinnipedimorpha, Which includes the extinct Desmatophocidae, and extant Phocidae (earless seals), Otariidae (fur seals and sea lions), and Odobenidae (walruses). We tested for the presence of Cope's rule by Compiling a large dataset of body size data for extant and fossil pinnipeds And Then Examined how body size evolved through time. We found thatthere was a positive relationship between geologic age and body size. However, this trend is the result of differences between early assemblages of small-bodied pinnipeds (Oligocene to early Miocene) and later assemblages (middle Miocene to Pliocene) for Which species exhibited Greater size diversity. No significant differences were found between the number of Increases or decreases in body size within Pinnipedimorpha or within specified pinniped clades. This Suggests That the pinniped body size Increase was driven by passive diversification into vacant niche space, with the common ancestor of Pinnipedimorpha Occurring near the minimum adult body size possible for a Marine Mammal. Based upon the above results, the evolutionary history of pinnipeds Does not follow Cope's rule.

The argument 10:30 on Tuesday Jan. 27.

Sunday, January 18, 2015

Good Genes and Sexual Selection in Dung Beetles

Onthophagus taurus male and female comparison.jpg
"Onthophagus taurus male and female comparison" by Source (WP:NFCC#4). Licensed under Fair use via Wikipedia.
Posted by Jessica Abbott for Jessica Åhlén-Sandblom 

This article by Garcia-Gonzalez and Simmons focus on the importance of the good genes model in female mate choice. 
One founding component of sexual selection is the existence of heritable variation in fitness. The good genes model tells us that this variance in quality is expressed phenotypically in the males and that females base their mate choice upon a trait that represent the male's good genes. 
The dung beetle has shown condition dependence of sexually selected traits and genetic correlations between preference and trait, thus comes the logical next step to see if the fitness of the father is inherited to the offspring.
Here they do a quantitative genetic analysis with a full-sib/half-sib design to compare the additive genetic effect of father on egg to adult and adult viability between families (one male mated with three females). 
They found a significant effect of the father for egg to adult viability and survival of sons but not daughters to adult age and no indication for sexual antagonism in genetic variation for fitness.
The authors argue for pre- and post-copulatory choice from females and competition between males to give the female indirect benefit in terms of higher offspring fitness in agreement with the good genes model.

Although this is not my current topic of research, I decided to share this article with you for three reasons. 
First of all, I have the possibility to do a similar project with Leigh Simmons (one of the authors) as my supervisor in the future, second because it relates with my ongoing project since they investigate paternally inherited fitness in a quantitative genetic study with a full-sib/half-sib breeding design and also discuss sexual antagonism briefly. And last, because it is short and neat (only 4 pages).

See you on Tuesday!
Jessica Åhlén Sandblom

 
Abstract: Whether species exhibit significant heritable variation in fitness is central for sexual selection. According to good genes models there must be genetic variation in males leading to variation in offspring fitness if females are to obtain genetic benefits from exercising mate preferences, or by mating multiply. However, sexual selection based on genetic benefits is controversial, and there is limited unambiguous support for the notion that choosy or polyandrous females can increase the chances of producing offspring with high viability. Here we examine the levels of additive genetic variance in two fitness components in the dung beetle Onthophagus taurus. We found significant sire effects on egg-to-adult viability and on son, but not daughter, survival to sexual maturity, as well as moderate coefficients of additive variance in these traits. Moreover, we do not find evidence for sexual antagonism influencing genetic variation for fitness. Our results are consistent with good genes sexual selection, and suggest that both pre- and postcopulatory mate choice, and male competition could provide indirect benefits to females.

Monday, January 5, 2015



Tobias is looking for three new postdocs and one lab manager to join the team!


I am currently recruiting people to join my group. To see what projects we currently work on, please visit my homepage.

There are now three postdoctoral positions available (described here and here) and one position as lab manager (will be advertised here shortly, please contact me if you want information).


Postdoc on sexual selection and introgression

The first position is a 2+1 year postdoc to study sexual selection and genomic introgression in wall lizards (funded by the Swedish Research Council). Over the past years we have done a lot of ground work to establish the causes of, and hence predictions for, the extent and direction of hybridization between divergent wall lizard lineages. The next step is to test these predictions in different hybrid contexts; in native hybrid zones and in several regions of secondary contact resulting from human translocations of the species within Europe.


Wall lizards (Podarcis muralis) from western Europe (left photos) are hybridizing with wallies from Italy (right photos). 

We are now looking for a highly motivated postdoc with experience of analysis of highthroughput sequencing data and with an interest in applying these tools to fundamental questions in evolutionary ecology. You could, for example, have done a PhD and/or postdoc in molecular ecology, evolutionary genomics, or phylogeography. With the freezer full of samples it is all ready to go, but there will be plenty of opportunities for field work as well (Italy, France, Germany, England...).


Field locations in Italy. Yes, most of our sites are like this.


Two Postdocs in Eco-Evo-Devo

I am also advertising two 2-year postdoc scholarships. These are intended to enable early career researchers to develop interesting, cutting-edge, research projects together with us. The positions therefore provide a lot of academic freedom - together we design a project that we feel is really exciting and that breaks new ground. Maybe something that truly advances our understanding of the role of development in evolution or that fit nicely within eco-evo-devo? Lizards, Daphnia, or maybe bring your own system? The funding for these scholarships and the research comes from my Wallenberg Academy Award.

Please apply if you are interested in our work, have the necessary skills and background, and if you you want to join a highly creative environment where we strive for both conceptual and empirical advances. For informal contact or questions, please send me an email. 


We like to work on lizards (currently Wallies, Egernia, Anolis) and Daphnia but are happy to discuss alternative systems as well. (Photo credits to Ben Halliwell and Stew Plaistow)

Lab Manager/Research Assistant

Finally, I am looking for a highly skilled and motivated lab manager/research assistant who want to be involved in the day-to-day running of the research group. This is a creative, flexible, and varied job as an important member of the research team, but without the expectation to independently secure funding and design and execute research projects. Tasks may involve assistance during data collection in the field, animal or molecular laboratory, support for data extraction, handling and statistical analyses, and coordination and management of the group's daily routines, including animal husbandry and administrative support.

If you have an MSc or PhD in a relevant area of biology and want a highly varied and creative job with plenty of responsibility this may be the perfect position for you. Our research involves field work, captive animals, and molecular analyses. What proportion of time you will spend on these depends on your background and interest, but we hope that you want to get involved in our research in many ways and take opportunities to learn new skills. The details of the position will appear here soon, but if you want to know more straight away please contact me.