Titleimage: Evolutionary Ecology


The Division of Evolutionary Ecology is interested in understanding both the proximate genetic mechanisms and ultimate ecological causes of evolutionary processes, such as adaptation to divergent environments, the formation of new species, and the evolution of sex chromosomes. Our main model system is a small fish called the threespine stickleback (Gasterosteus aculeatus) and its close relatives in the stickleback family (Gasterosteidae). These fish have adapted to a variety of marine and freshwater habitats across the Northern hemisphere and consequently evolved incredible diversity in their behaviors, morphologies, life histories, and sex chromosomes on a relatively short evolutionary time scale. The development of genetic and genomic tools for these fish has allowed us to identify specific genetic, genomic, and molecular changes that underlie this phenotypic diversity and that contribute to reproductive isolation between phenotypically and ecologically divergent populations.




Dr. Zuyao Liu successfully defends his PhD

Congratulations to Dr. Zuyao Liu, who successfully defended his thesis entitled “Exploring the Evolutionary Significance of Chromosomal Fusions and Inversions: Implications for Adaptive Evolution and Sex Chromosome Evolution”. Zuyao gave a beautiful talk and impressed his defense committee with his thoughtful answers to their questions. Special thanks to Qi Zhou for serving as the external examiner and Claudia Bank for chairing the defense, as well as Sam Yeaman for co-supervision of Zuyao during his PhD. After a well-deserved vacation in China, Zuyao will start a new adventure as a postdoc studying the role of inversions in adaptation. Lucky for us, he will stay right here in the Division of Evolutionary Ecology!

Matt Josephson, Diana Rennison, and Matt Zuellig

Global Urban Evolution Project published in Science

During their time as postdocs in the Division of Evolutionary Ecology, Matt Josephson, Diana Rennison, and Matt Zuellig collected white clover from a urban to rural cline in Bern as part of the Global Urban Evolution project led by Marc Johnson at the University of Toronto. A paper describing the results of this worldwide study, based on 110,019 plants from 6169 populations in 160 cities from 26 countries was just published in Science. This large dataset demonstrates that adaptation to urban environments drives the evolution of hydrogen cyanide production (an antiherbivore chemical defense) and further identifies specific environmental factors that influence whether urban-rural clines evolve in parallel. Glad that we could make a small contribution to such a cool project!

The Ecology and Biogeography of Sri Lanka: A context for freshwater fishes

The Ecology and Biogeography of Sri Lanka: A context for freshwater fishes

Hiranya Sudasinghe, a joint PhD student with Lukas Rüber at the Natural History Museum of Bern, has published a book! Despite advances in biodiversity exploration, the origins of Sri Lanka's fauna and flora have never yet been treated in a synthetic work. This book draws together the threads that make up that fascinating 100-million year story. Encompassing the island's entire biota while emphasising the ecology, biogeography and phylogeography of freshwater fishes, it provides a comprehensive context for understanding how the island's plants and animals came to be as they are. The 258-page text contains more than 200 figures, photographs and maps. It provides a clear account of how, when and from where the ancestors of the plants and animals that now inhabit Sri Lanka came. For the first time, the island's unique biodiversity can be understood and appreciated in its historical and evolutionary context in this invaluable sourcebook, designed for scientists, students and biodiversity enthusiasts alike.

Introduction to Genetic Analysis

Katie Peichel is an author on the new edition of the Introduction to Genetic Analysis textbook

The 12th edition of the Introduction to Genetic Analysis textbook has just been released. Katie Peichel revised and updated the chapters on Genetics and Genomics, Developmental Genetics, Chromosomal Changes, and Evolution. She added content on next-generation sequencing methods and analyses, as well as an evolutionary perspective on genetic analyses in non-traditional model organisms throughout these chapters. Katie was honoured to be an author on the same textbook (5th edition) she used as an undergraduate studying genetics at UC Berkeley many years ago!


New paper by students from the Evolutionary Ecology research practical

Students Michelle Gygax and Ana Rentsch recently published a paper in the Journal of Evolutionary Biology in which they report the results of a project they conducted under the supervision of Dr. Diana Rennison during the 2016 Evolutionary Ecology research practical. They found that threespine sticklebacks raised in ponds with a predator (cutthroat trout) exhibited more lateral barring (stripes) than threespine sticklebacks raised in ponds without the predator. An increase in the presence of vertical barring was correlated with an increase in water clarity and littoral habitat use. These data provide experimental evidence to support the hypothesis that vertical barring has evolved in sticklebacks due to selection by visual predators for cryptic coloration in vegetated habitats.


Genetic coupling of female traits and female preference facilitates speciation

How are associations between traits under divergent selection and traits that contribute to assortative mating maintained in the face of gene flow during ecological speciation? In a new paper in Current Biology, Catherine Peichel, Dolph Schluter (University of British Columbia) and colleagues answer this question using a classic model of ecological speciation, sympatric benthic-limnetic sticklebacks. To allow for recombination between loci underlying assortative mating and those under divergent ecological selection, they assessed the mate choice of benthic-limnetic stickleback F2 hybrid females for wild benthic or limnetic males under natural conditions in ponds. Remarkably, F2 females chose males with a similar body shape and size to their own. Furthermore, genetic loci associated with F2 female mate choice also predicted F2 female morphology. These data provide empirical evidence to support the long-standing theoretical prediction that genetic coupling between assortative mating and traits under divergent selection can facilitate speciation in the face of gene flow.


New Head of Division Evolutionary Ecology

Prof Dr Catherine (Katie) Peichel is excited to join the IEE as a new Professor and Head of the Division Evolutionary Ecology as of August 1. Katie is a geneticist with interests in the genetic and genomic changes that underlie phenotypic evolution, including adaptation, sex chromosome evolution, behavior and speciation. Before joining the IEE, Katie led a research group at the Fred Hutchinson Cancer Research Center in Seattle and was an Affiliate Professor in the Department of Biology at the University of Washington.



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