Lab-meeting on ERC-interview, PNAS-accept, niche-filling, supply and demand and avian species richness in the Himalayas

Next week, we will listen to Jessica Abbott, giving her "practice talk" before her interview in Brussels (Belgium) for an ERC Junior Grant, which we certainly hope she will get this time (it is the second year in a row that Jessica has been shortlisted for this prestiguous grant). We should all try to give good feedback to Jessica so that her chances to get this grant are maximized!

We will also celebrate that Jessica, I, our two former postdocs Natsu and Yuma and Jostein Kjaerandsen got an accept on our paper on sexual selection on Wing Interference Patterns (WIP:s) in Drosophila melanogaster in Proc. Natl. Acad. Sci. USA. Jessica has promised to bring some nice "fika", and I will bring some "bubble" to celebrate this.

Finally, Jessica asked me to pick a short paper to discuss as well, and I have chosen a relatively recent paper on adaptive radiation, speciation and niche filling in the Himalayan bird fauna. I do this partly for personal reasons, as this is a fascinating and extremely species-rich region of the world where I travelled as a young student and avid bird watcher in 1991, just before the start of my PhD in 1992. I hope you will enjoy this beatiful paper (Abstract is provided below). You might also want to read the "News and Views" comment on this paper by Arne Mooers, which summarizes the main findings.

Date and time: Tuesday, September 23, 10.30
Where: "Argumentet", 2nd floor, Ecology Building. 
  
Trevor D. Price et al.

Niche filling slows the diversification of Himalayan songbirds

Nature 509, 222–225 (08 May 2014) doi:10.1038/nature13272

Speciation generally involves a three-step process—range expansion, range fragmentation and the development of reproductive isolation between spatially separated populations1, 2. Speciation relies on cycling through these three steps and each may limit the rate at which new species form1, 3. We estimate phylogenetic relationships among all Himalayan songbirds to ask whether the development of reproductive isolation and ecological competition, both factors that limit range expansions4, set an ultimate limit on speciation. Based on a phylogeny for all 358 species distributed along the eastern elevational gradient, here we show that body size and shape differences evolved early in the radiation, with the elevational band occupied by a species evolving later. These results are consistent with competition for niche space limiting species accumulation5. Even the elevation dimension seems to be approaching ecological saturation, because the closest relatives both inside the assemblage and elsewhere in the Himalayas are on average separated by more than five million years, which is longer than it generally takes for reproductive isolation to be completed2, 3, 6; also, elevational distributions are well explained by resource availability, notably the abundance of arthropods, and not by differences in diversification rates in different elevational zones. Our results imply that speciation rate is ultimately set by niche filling (that is, ecological competition for resources), rather than by the rate of acquisition of reproductive isolation.

Climatic niche similarity and geographic range limits in ecologically similar co-existing damselflies

Dear all,
Now it is time to discuss one of my papers again. Together with Keith Larson and Erik Svensson, I am currently working on a paper that investigates niche divergence in Calopteryx damselflies.

Speciation in the genus Calopteryx is largely thought to be de-coupled from ecology, and reproductive isolation seems to have evolved independent of habitat ecology, through sexual selection, social interactions, learning and/or genetic incompatibilities. For this reason, ecological differences between closely related odonates are a priori expected to be relatively minor, and the modest differences that exist are likely to have evolved post-speciation, reflecting ecological divergence after reproductive isolation was already achieved. We tested these predictions using a large habitat data set for the two largely co-existing species Calopteryx splendens and C. virgo in Sweden and Finland and then employed spatial modelling techniques to identify the:

(i) environmental habitat characteristics, amount of niche overlap and degree of habitat specialisation,

(ii) combined and interactive effects of environment and predators and

(iii) ecological differences between allopatric and sympatric populations.

It will be great to discuss our findings with you next week (as usual we meet on Wednesday the 6th of October at 10:15 at the Darwin room, Lund University). Erik has also suggested to read a recent paper by John E. McCormack, Amanda J. Zellmer, and L. Lacey Knowles. Their work focused on niche divergence and its role in speciation in Mexican Jays.

DOES NICHE DIVERGENCE ACCOMPANY ALLOPATRIC DIVERGENCE IN APHELOCOMA JAYS AS PREDICTED UNDER ECOLOGICAL SPECIATION?: INSIGHTS FROM TESTS WITH NICHE MODELS

I will circulate the Evolution paper by McCormack et al. (2010) and the manuscript via email. If I have not included you in the email list and you would like to read and comment on these papers, then please send an email Maren.Wellenreuther@zooekol.lu.se

I will bring fika to the next meeting.

Have fun, Maren