Evolution of Plasticity in Response to Ethanol between Recently Separated Populations ofD. melanogasterwith Different Ecological Histories

Abstract

AbstractThe evolution of phenotype plasticity by genetic accommodation was theorized but has not been extensively demonstrated. Under this model of evolution when a population encounters a new environment there are widely variable responses amongst different genotypes, which are then pruned by selection into a single adaptive response. Because of the requirement to replicate genotypes, testing this predication requires inbred lines as well as populations that are both adapted and not adapted to a resource. We previously demonstrated thatD. melanogasteradapted to ethanol through genetic accommodation usingD. simulansas an ancestral proxy lineage. However, we wondered how generalizable these results were. Using a new population ofD. melanogasterfrom France and an ancestral range population from Zambia we demonstrated here that the Zambian population is not adapted to ethanol and that the French population has evolved ethanol resistance through genetic accommodation. We also investigated alternative splicing in response to ethanol and find that gene expression and splicing appear to evolve independently of one another, and that the splicing response to ethanol is largely distinct between populations. Thus we have independently replicated evidence for evolution by genetic accommodation inD. melanogaster, suggesting that the evolution of plasticity may be an important contributor to the ability to exploit novel resources.