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Université de Fribourg

Parasite‐driven replacement of a sexual by a closely related asexual taxon in nature

Lohr, Jennifer N. ; Haag, Christoph R.

In: Ecology, 2020, vol. 101, no. 10, p. -

Asexual species are thought to suffer more from coevolving parasites than related sexuals. Yet a variety of studies do not find the patterns predicted by theory. Here, to shine light on this conundrum, we investigate one such case of an asexual advantage in the presence of parasites. We follow the frequency dynamics of sexual and asexual Daphnia pulex in a natural pond that was initially...

Université de Fribourg

Distinct genomic signals of lifespan and life history evolution in response to postponed reproduction and larval diet in Drosophila

Hoedjes, Katja M. ; van den Heuvel, Joost ; Kapun, Martin ; Keller, Laurent ; Flatt, Thomas ; Zwaan, Bas J.

In: Evolution Letters, 2019, p. -

Reproduction and diet are two major factors controlling the physiology of aging and life history, but how they interact to affect the evolution of longevity is unknown. Moreover, although studies of large‐effect mutants suggest an important role of nutrient sensing pathways in regulating aging, the genetic basis of evolutionary changes in lifespan remains poorly understood. To address these...

Université de Fribourg

How clonal are clones? A quest for loss of heterozygosity during asexual reproduction in Daphnia magna

Dukić, Marinela ; Berner, Daniel ; Haag, Christoph R. ; Ebert, Dieter

In: Journal of Evolutionary Biology, 2019, vol. 32, no. 6, p. 619–628

Due to the lack of recombination, asexual organisms are predicted to accumulate mutations and show high levels of within‐individual allelic divergence (heterozygosity); however, empirical evidence for this prediction is largely missing. Instead, evidence of genome homogenization during asexual reproduction is accumulating. Ameiotic crossover recombination is a mechanism that could lead to...

Université de Fribourg

Evolution of gene expression during a transition from environmental to genetic sex determination

Molinier, Cécile ; Reisser, Céline M O ; Fields, Peter D ; Ségard, Adeline ; Galimov, Yan ; Haag, Christoph R

In: Molecular Biology and Evolution, 2019, vol. 36, no. 7, p. 1551–1564

Genetic sex determination (GSD) can evolve from environmental sex determination (ESD) via an intermediate state in which both coexist in the same population. Such mixed populations are found in the crustacean Daphnia magna, where non-male producers (NMP, genetically determined females) coexist with male producers (MP), in which male production is environmentally inducible and can also...

Université de Fribourg

The diversity of population responses to environmental change

Colchero, Fernando ; Jones, Owen R. ; Conde, Dalia A. ; Hodgson, David ; Zajitschek, Felix ; Schmidt, Benedikt R. ; Malo, Aurelio F. ; Alberts, Susan C. ; Becker, Peter H. ; Bouwhuis, Sandra ; Bronikowski, Anne M. ; Vleeschouwer, Kristel M. ; Delahay, Richard J. ; Dummermuth, Stefan ; Fernández‐Duque, Eduardo ; Frisenvænge, John ; Hesselsøe, Martin ; Larson, Sam ; Lemaître, Jean‐François ; McDonald, Jennifer ; Miller, David A.W. ; O'Donnell, Colin ; Packer, Craig ; Raboy, Becky E. ; Reading, Chris J. ; Wapstra, Erik ; Weimerskirch, Henri ; While, Geoffrey M. ; Baudisch, Annette ; Flatt, Thomas ; Coulson, Tim ; Gaillard, Jean‐Michel

In: Ecology Letters, 2019, p. -

The current extinction and climate change crises pressure us to predict population dynamics with ever‐greater accuracy. Although predictions rest on the well‐advanced theory of age‐structured populations, two key issues remain poorly explored. Specifically, how the age‐dependency in demographic rates and the year‐to‐year interactions between survival and fecundity affect...

Université de Fribourg

Evolution of longevity improves immunity in Drosophila

Fabian, Daniel K. ; Garschall, Kathrin ; Klepsatel, Peter ; Santos-Matos, Gonçalo ; Sucena, Élio ; Kapun, Martin ; Lemaitre, Bruno ; Schlötterer, Christian ; Arking, Robert ; Flatt, Thomas

In: Evolution Letters, 2018, vol. 2, no. 6, p. 567–579

Much has been learned about the genetics of aging from studies in model organisms, but still little is known about naturally occurring alleles that contribute to variation in longevity. For example, analysis of mutants and transgenes has identified insulin signaling as a major regulator of longevity, yet whether standing variation in this pathway underlies microevolutionary changes in...