UCL Division of Biosciences


GEE Seminar - Professor Catherine (Katie) Peichel, Universitat Bern

16 January 2024, 12:00 pm–1:00 pm

Title: ‘The role of chromosomal rearrangements in adaptation and speciation in sticklebacks’

Event Information

Open to

UCL staff | UCL students | UCL alumni




Amy Godfrey


Room 05
188 Tottenham Court Road

Academic Host: Wenying Shou
Abstract: Many species have dramatic differences in chromosome number and structure. Early evolutionary biologists thought that these differences in karyotype within and between species were drivers of adaptation and speciation, an idea that is currently undergoing a renaissance of interest. However, we know little about the molecular mechanisms that underlie how changes in karyotype occur, and we have little direct evidence to support a role for these karyotype changes in adaptation and speciation. Using both classical cytogenetic methods as well as modern whole-genome sequencing approaches, we have found a diversity of chromosomal changes among species of the stickleback family of fish. These include changes in overall chromosome number due to chromosomal fusions, changes to the sex chromosome system, and chromosomal inversions. I will present our work linking these chromosomal changes to reproductive isolation between closely related species, as well as adaptation within species.

About the Speaker

Professor Catherine (Katie) Peichel

Head of the Division Evolutionary Ecology at Universitat Bern

What are the genetic and genomic changes that underlie phenotypic evolution? How do these changes lead to adaptation to new environments and the formation of new species? Although these questions are of longstanding interest to evolutionary biologists, until recently they have been intractable, particularly in vertebrate species. In order to address these questions, I have helped to develop the threespine stickleback fish (Gasterosteus aculeatus) as a model system for evolutionary genetics and genomics. Work conducted during my postdoctoral fellowship with David Kingsley focused on the genetic basis of morphological variation in sticklebacks. Since starting my own laboratory in 2003, first at the Fred Hutchinson Cancer Research Center in Seattle and now at the University of Bern, I have investigated the genetic and genomic mechanisms that underlie morphological, behavioral, and physiological traits that differ between stickleback populations that have adapted to divergent habitats. These studies have provided important insights into the genetic architecture of phenotypic evolution, adaptation and speciation, as well as the evolution of sex chromosomes. My laboratory has also begun to examine the effects of natural selection on these genetic variants in the wild.

My long-term goals are to combine genetic and genomic approaches in the lab with evolutionary and ecological studies in the field to tackle three fundamental questions in evolution: (1) what is the genetic and genomic basis of adaptation and speciation?; (2) what is the genetic and neural basis of behavioral evolution?; and (3) how and why do sex chromosomes evolve?

More about Professor Catherine (Katie) Peichel