Centro de Biologia Ambiental / Departamento de Biologia Animal
Fac. Ciências Univ. Lisboa Campo Grande, Building C2 Floor 1
Abstracts (first author)
Variable association between inversions and wing traits in Drosophila subobscura: are there consistent differences between continents?PDF
Clinal variation for wing size and shape as well as for chromosomal inversion frequencies has been found in Drosophila subobscura from Europe as well as North and South America. Particularly it has been reported that standard arrangements increase in frequency towards higher latitudes, where flies are also bigger. In the New World the rapid evolution of body size clines as a follow up of clinal evolution of inversions, suggested that the wing traits cline had been driven by the inversion polymorphism. Previous studies, in favor of this hypothesis, found an intra-population association between wing traits (size and shape) and standard chromosomal inversions. Nevertheless, it was also found that the association (for shape) or details of it (for size) had opposite signs in one European population (Adraga) and one South American population (Puerto Montt). This is probably due to a bottleneck effect following the colonization of the Americas. Despite this interesting finding it is still unknown if this is a generalized difference between continents. To tackle this question we here tested for the consistency of the association between wing traits and inversions in three populations along the cline of Europe as well as South America. Surprisingly we found no clear association between wing size and the number of standard inversions in either continent. On the other hand, we confirmed that the previously reported negative association between wing shape and standard dose of Puerto Montt spread with latitude through other South America populations. This is not in agreement with the positive sign of the cline for both wing shape and inversions. Overall and contrary to previous indications, this study suggests that the inversion and wing clines in D. subobscura have evolved independently from each other.