Minisymposium May 24 2012: "Biogeography and Evolution"

We are happy to announce an exciting Minisymposium entitled "Biogeography and Evolution" on May 24 2012 that will take place on the afternoon the day preceeding Anna Runemarks PhD-thesis defence (May 25). We have four excellent speakers that will present some exciting talks this afternoon. This symposium is open for everyone, whether from the Biology Department of from elsewhere. Full details of the programme and the titles of the talks are presented below:

Minisymposium on Biogeography and 

Evolution

                 

May 24, 13.00 - 16.00                               

"Blue Hall", Ecology Building, Department of Biology, Lund

13.00-13.40 Scott V. Edwards (Harvard University, USA)  “The phylogeography-phylogenetics continuum: a look to the future”

13.50-14.20 Jessica Ware (Rutgers University, USA) "Here be dragons: biodgeography and age of Petaluridae, the petaltail dragonflies"

14.30-14.50 Coffee

14.50 - 15.20 Alexandre Antonelli (Gothenburg University, Sweden) "Ecology meets Biogeography: A Multi-Disciplinary Approach to Study Neotropical Diversification"

15.30- 15.50 Folmer Bokma (Umeå University, Sweden) ”Why species may not adapt”

15.50 - 16.00 Discussion and concluding remarks

Symposium open for all interested. No registration required.

Welcome!


Bengt Hansson, Anna Runemark & Erik Svensson

New journal cover in Molecular Ecology: Vicariance divergence and gene flow among islet populations of an endemic lizard

I study genetic, morphological and behavioural divergence in islet populations of the Skyros wall lizard, Podarcis gaigeae. This species shows strong morphological divergence, including island gigantism (see the cover image, with adult male lizards from mainland populations to the left and islet populations to the right ). In this paper (found here) we have used isolation with migration models to investigate divergence times and levels of gene flow between islet populations and their closest mainland populations. Such background information is valuable for example for inferring rates of morphological and genetical divergence. Our results support that the studied islet populations have been sequentially separated by rising sea levels in the Aegean.

Abstract:

Allopatry and allopatric speciation can arise through two different mechanisms: vicariance or colonization through dispersal. Distinguishing between these different allopatric mechanisms is difficult and one of the major challenges in biogeographical research. Here, we address whether allopatric isolation in an endemic island lizard is the result of vicariance or dispersal. We estimated the amount and direction of gene flow during the divergence of isolated islet populations and subspecies of the endemic Skyros wall lizard Podarcis gaigeae, a phenotypically variable species that inhabits a major island and small islets in the Greek archipelago. We applied isolation-with-migration models to estimate population divergence times, population sizes and gene flow between islet–mainland population pairs. Divergence times were significantly correlated with independently estimated geological divergence times. This correlation strongly supports a vicariance scenario where islet populations have sequentially become isolated from the major island. We did not find evidence for significant gene flow within P. g. gaigeae. However, gene-flow estimates from the islet to the mainland populations were positively affected by islet area and negatively by distance between the islet and mainland. We also found evidence for gene flow from one subspecies (P. g. weigandi) into another (P. g. gaigeae), but not in the other direction. Ongoing gene flow between the subspecies suggests that even in this geographically allopatric scenario with the sea posing a strong barrier to dispersal, divergence with some gene flow is still feasible.