EvoLunch Seminar: Thomas Bataillon (Aarhus University)
EvoLunch Seminar
Adaptation to climate change and the genetic basis of ecotypic differentiation in wild thyme
"Adaptation to climate change and the genetic basis of ecotypic differentiation in wild thyme."
11:00 CET
Location TBA, ISTA
Hybrid Meeting (for zoom link, email evolunch.seminar@ist.ac.at)
| Common thyme (Thymus vulgaris), a dominant shrub of Mediterranean garrigue vegetation, displays a striking monoterpene-based chemical polymorphism, with populations dominated by one of several distinct chemotypes. In the St Martin de Londres valley (southern France), six chemotypes fall into two functional groups—phenolic (thymol, carvacrol) and non-phenolic (linalool, thujanol, α-terpineol, geraniol)—whose distribution tracks a sharp microclimatic gradient driven by winter temperature inversions. Reciprocal transplant experiments show these chemotypes correspond to distinct ecotypes: phenolic types favored under hot, dry summers, and non-phenolic types better adapted to harsh winters. Recent decades of climate warming have weakened winter frosts in the valley, and phenolic ecotypes have correspondingly expanded into areas once dominated by non-phenolic plants, offering a rare real-time view of climate-driven adaptive turnover. While the genetic basis of this polymorphism has recently been characterized at the local scale, it remains unknown whether similar ecotypic transitions and their underlying genetic architecture are repeated across broader geographic scales, or reflect independent, region-specific adaptive events. We address this by sampling ca 1000 T. vulgaris along > 60 populations spanning nine independent elevational climate gradients across mountainous southern France, providing a framework to test for parallelism in the genetic basis of climate adaptation. We discuss the findings and how they inform us on our ability to infer genomics of local adaptation with/without phenotypic information. |