Evolutionary ecology of a widespread green-brown polymorphism in grasshoppers

Holger Schielzeth
Population Ecology Group, University of Jena, Germany

holger.schielzeth@uni-jena.de

The coexistence of multiple colour morphs in natural populations has fascinated ecologists and evolutionary biologists for a long time, begging the question how such phenotypic polymorphisms are maintained in the long run. One of the most remarkable systems of widespread coexistence of discrete colour morphs is the green-brown polymorphism in Orthopterans. A large number of species, mostly those inhabiting grasslands, occur in both green and brown variants in natural populations and their coexistence appears to depend on the action of balancing selection. I will introduce the fascinating study system and present recent ecological, quantitative genetic and genomic work that aims to uncover the selective conditions that contribute to the maintenance of the polymorphisms as well as its genetic basis. Besides the specific case of grasshoppers, I will also touch upon the concept of the ecological niche that I think needs a fresh-up when viewed from the perspective of an evolutionary ecologist.

Recent publications:

Nakagawa, S., Johnson, P.C.D. & Schielzeth, H. (2017). The coefficient of determination R² and intra-class correlation coefficient from generalized linear mixed-effects models revised and expanded. Journal of the Royal Society Interface 14: 20170213. 

Schielzeth, H., Rios Villamil, A. & Burri, R. (2018). Success and failure in replication of genotype-phenotype associations: How does replication help in understanding the genetic basis of phenotypic variation in outbred populations? Molecular Ecology Resources 4: 739-754.

de Villemereuil, P., Schielzeth, H., Nakagawa, S. & Morrissey, M. (2016). General methods for evolutionary quantitative genetic inference from generalised mixed models. Genetics 204: 1281-1294.