Mecanismes genètics i ecològics que promouen biodiversitat en comunitats naturals: un estudi organísmic i molecular en "drosophila"

We want to investigate the mechanisms that promote biodiversity using various approaches ranging from the ecological to the molecular. The model system of cactophilic natural communities of "Drosophila" will be used because it allows to perform ecological and genetic studies simultaneously. Two communities have been chosen: one in north-western Argentina, the original site of "D.buzzatii" and "D.koepferae", the other in south-eastern Spain, in the mediterranean locality of Carboneras, which has been colonized by "D.buzzatii". Two hypotheses which explain the observed intra- and interspecific diversity in these communities will be tested: a) the hypothesis of trade-offs between fitness components; b) the spatial heterogeneity and breeding structure hypothesis. The population structure studies will be carried out using a set of genetic markers that are affected to different degrees by natu