Data from: Fitness surfaces and local thermal adaptation in Drosophila along a latitudinal gradient

Résumé

Local adaptation is commonly cited to explain species distribution, but how fitness varies along continuous geographical gradients is not well understood. Here we combine thermal biology and life-history theory to demonstrate that Drosophila populations along a 2,500 km latitudinal cline are adapted to local conditions. We measured how heat tolerance and viability rate across 8 populations vary with temperature in the laboratory, and then simulated their expected cumulative Darwinian fitness employing high-resolution temperature data from their 8 collection sites. Simulations indicate a trade-off between annual survival and cumulative viability, as both mortality and the recruitment of new flies are predicted to increase in warmer regions. Importantly, populations are locally adapted and exhibit the optimal combination of both traits to maximize fitness where they live. In conclusion, our method is able to reconstruct fitness surfaces employing empirical life-history estimates and reconstructs peaks representing locally adapted populations, allowing to study geographic adaptation in silico.