Continent-wide differentiation of fitness traits and patterns of climate adaptation among European populations of Drosophila melanogaster

A particularly well-studied evolutionary model is the vinegar fly Drosophila melanogaster, a cosmopolitan insect of ancestral southern-central African origin. Recent work suggests that it expanded out of Africa similar to 9,000 years ago, and spread from the Middle East into Europe similar to 1,800 years ago. During its global expansion, this human commensal adapted to novel climate zones and habitats. Despite much work on phenotypic differentiation and adaptation on several continents (especially North America and Australia), typically in the context of latitudinal clines, little is known about phenotypic divergence among European populations. Here, we sought to provide a continent-wide study of phenotypic differentiation among European populations of D. melanogaster. In a consortium-wide phenomics effort, we assayed 16 fitness-related traits on a panel of 173 isofemale lines from 9 European populations, with the majority of traits measured by several groups using semi-standardized protocols. For most fitness-related traits, we found significant differentiation among populations on a continental scale. Despite inevitable differences in assay conditions among labs, the reproducibility and hence robustness of our measurements were overall remarkably good. Several fitness components (e.g., viability, development time) exhibited significant latitudinal or longitudinal clines, and populations differed markedly in multivariate trait structure. Notably, populations experiencing higher humidity/rainfall and lower maximum temperature showed higher viability, fertility, starvation resistance, and lifespan at the expense of lower heat-shock survival, suggesting a pattern of local adaptation. Our results indicate that derived populations of this tropical fly have been shaped by pervasive spatially varying multivariate selection and adaptation to different climates on the European continent.

Vrije Universiteit Amsterdam
INRAE
Universität Utrecht
Aarhus university
Czech Academy of Sciences
Georg-August-Universität Göttingen
University of Richmond
Ministry of Education & Science of Ukraine
University of South Bohemia Ceske Budejovice
Instituto Gulbenkian de Ciencia
Flinders University South Australia
DrosEU
University of Groningen
Martin-Luther Universität Halle-Wittenberg
University of Pennsylvania
University of Virginia
University of Fribourg
European Molecular Biology Laboratory (EMBL)
University of Haifa
Consejo Superior de Investigaciones Cientificas (CSIC)
University of Lausanne
University of Buenos Aires
University of Southern Denmark
Hacettepe University
Universidade de Lisboa
University of Wurzburg
Lund University
Wageningen University & Research
University of Jyvaskyla
Centre National de la Recherche Scientifique (CNRS)
University of St Andrews
Universidade do Porto
University of Belgrade
Russian Academy of Sciences
University of Liverpool
University of Munich
Harvard University