Local adaptation of development time and starvation resistance in eight Drosophila species of the Philippines.
Kim van der Linde & Jan G. Sevenster (2006)
Biological Journal of the Linnean Society , 87: 115-125.
The ecological trade-off between development time and starvation resistance,
acting in a heterogeneous environment can promote the coexistence of competing
species. Heterogeneity results from variation in the vegetation that influences
both abiotic (e.g. temperature, humidity) and biotic aspects (e.g. fruit
availability during the year) of the environment. In this study, we
investigated whether differences between the habitats have led to local
adaptation of the two life-history traits underlying the model: development
time and starvation resistance. Drosophila 's were collected in four habitats,
ranging from grassland to secondary forest, along a transect of 15 kilometres.
The microclimatic and vegetation differences among these habitats were
considerable. For development time, different species showed similar genetic
responses to different habitats. The shortest development times were found in
the secondary forest populations and the agricultural area populations, the
longest in the grassland populations while the forest edge populations were
intermediate. However, there was no correlation between the habitat ranking
based on disturbance and canopy cover, and the ranking of the development
times. Local selection did not seem to have a consistent effect on starvation
resistance. Furthermore, the data did not confirm the generality of the
positive correlation underlying the coexistence model.