Last EXEB-meeting in 2016 on December 20: hard and soft selection revisited

Posted by Erik Svensson

Nathalie and I decided to have a final EXEB-meeting of the year next week anyway, even though nothing was planned. Nathalie will bring "fika", and I will introduce a review paper (hopefully a light read) on "hard" and "soft" selection; two very important concepts that illustrate the difference between ecological and population genetic views of how selection works. Title and Abstract of the paper follows below.

When: Tuesday, December 20 at 10.00
Where: "Darwin, 2nd floor, Ecology Building

 Hard and Soft Selection Revisited: How Evolution by Natural Selection Works in the Real World

by David Reznick ( J Hered (2015) doi: 10.1093/jhered/esv07)

Abstract

The modern synthesis of evolutionary biology unified Darwin’s natural selection with Mendelian genetics, but at the same time it created the dilemma of genetic load. Lewontin and Hubby’s (1966) and Harris’s (1966) characterization of genetic variation in natural populations increased the apparent burden of this load. Neutrality or near neutrality of genetic variation was one mechanism proposed for the revealed excessive genetic variation. Bruce Wallace coined the term “soft selection” to describe an alternative way for natural selection to operate that was consistent with observed variation. He envisioned nature as presenting ecological vacancies that could be filled by diverse genotypes. Survival and successful reproduction was a combined function of population density, genotype, and genotype frequencies, rather than a fixed value of the relative fitness of each genotype. My goal in this review is to explore the importance of soft selection in the real world. My motive and that of my colleagues as described here is not to explain what maintains genetic variation in natural populations, but rather to understand the factors that shape how organisms adapt to natural environments. We characterize how feedbacks between ecology and evolution shape both evolution and ecology. These feedbacks are mediated by density- and frequency-dependent selection, the mechanisms that underlie soft selection. Here, I report on our progress in characterizing these types of selection with a combination of a consideration of the published literature and the results from my collaborators’ and my research on natural populations of guppies.

Symposium on phenotypic plasticity in Lund: November 26-27 2012

Posted by Erik Svensson

Next week there will be no lab-meeting as there will instead be an exciting international symposium in our department on the evolution of phenotypic plasticity: November 26-27 (two full days). The program looks very exciting, with some wellknown researchers and international guests. For more information, contact Johan Hollander (johan.hollander@biol.lu.se).

Also, the week after there will not be a regular lab-meeting, as the Evolutionary Ecology Unit will have its annual "Christmas Meeting" between December 4 and 5. There will be research talks, social activites and Christmas Dinner. If you are affiliated with the Evolutionary Ecology Unit and would like to participate, contact Anne Fogelberg (anne.fogelberg@biol.lu.se) or Per Lundberg (per.lundberg@biol.lu.se).

Party to celebrate the new Biology Department on September 16 2010

You might know that we have formed a new Biology Department in Lund from January 1 this year, as a merger of two former departments: Department of Ecology and Department of Cell- and Organismal Biology (COB). On September 16, there will be a party and some talks and ceremonies to celebrate this, and all employees (including faculty members, PhD-students, postdocs and visiting researchers) are welcome to attend this event. You can sign up here for the party.

The new Biology Department will be organized in six new "units", consisting of about 50 persons in each unit. One of these new units will be Evolutionary Ecology, and it will be a new unit that merges all former member of the Theoretical Ecology, parts of Animal Ecology and Plant Ecology & Systematics. In my opinion, this will be a boost to the evolutionary ecology research in Lund, as it will increase our international visibility and (hopefully) also help to attract new co-workers, postdocs and students from Sweden and abroad.

Clearly, this will have a positive impact also on our research laboratory, as we will have the opportunity to interact and collaborate more closely with our theoretical ecology colleagues and plant quantitative geneticist Stefan Andersson in the future.