Adaptation, diversification and origins of biodiversity
Animator : Sébastien LAVERGNE
Over the last decade, evidence has increased that natural selection in heterogeneous environments, which leads to phenotypic divergence and local adaptation of populations, has been a major force of species diversification, with spectacular examples of ecological speciation and adaptive radiations. However, it remains unclear how the relative effects of adaptive and non-adaptive processes shape the distribution of phenotypic differences between species, or how the emergence and development of key morphologic and physiologic traits of high adaptive value within species ultimately lead to patterns of speciation and divergence between species.
To answer these important questions we must then bridge the long existing gap between microevolutionary processes and macroevolutionary patterns. This can only come from empirical studies aiming to analyse the evolution of phenotypic adaptations and the signatures of natural selection within a broader macroevolutionary context studying the diversification of species’ traits and niches.
The main objectives of this working group are the following :
1. Improve our understanding of the genetic basis of adaptation and reproductive isolation, by studying populations spread out along environmental gradients, or experiencing drastic natural or anthropic selection. Explore the effects of phenotypic plasticity by studying gene regulations and epigenetics, and how this plasticity contributes to phenotypic variation.
Keywords :genome-scans, genome-wide association studies, local adaptation, gene-flow, climatic gradients, xenobiotics, transcriptomics.
2. Study the adaptation of populations, the balance between disruptive natural selection and gene-flow, and how these processes shape hybrid zones and speciation. Study molecular signatures of adaptive radiation and ecological divergence in natural populations of closely related species.
3. Reconstruct the evolutionary origins of biodiversity patterns in order to decipher the tempo and mode of species diversification and how these have been influenced by environmental factors (biotic and abiotic) and key morphological innovations.
Study zones and biological models
The main scales of study and biological models encompass alpine plants of temperate and tropical regions (e.g. Androsace, Espeletia), butterflies (e.g. Coenonympha, Heliconius), wild and domestic ruminants (e.g. Capra, Ovis), mosquitoes and some bird clades (e.g. Charadriiformes).
Network and originalities
This research is conducted at the interface with other local laboratories from the university of Grenoble (applied mathematics, glaciology, geology) with the OSUG framework. Its originality stems from its common endeavour to bridge all organismic scales (from genes to entire clades) and timescales (few generations to million years).
This theme builds on current NGS technologies and bioinformatics, and biodiversity informatics (trait and distribution species databases).