Existence of geographical clines have equally attracted ecologists and evolutionary
biologists. In recent years our understanding of geographical clines has immensely improved.
The most promising pieces of evidence come from studies showing phenotypic change
observed over seasonal time scales i.e. temporal variation. Temporal variation in selection
pressures could be at least partially responsible for the generation of latitudinal clines that
appear so pervasive in Drosophila melanogaster. However, the connection between temporal
and spatial evolutionary dynamics of life histories remain to be comprehensively tested in
nature. Increasing recognition that evolutionary processes can operate on ecological time
scales has generated growing interest in eco-evolutionary dynamics, where evolutionary
change alters ecological interactions, which in turn, feed-back to alter subsequent
evolutionary change. Much of the interest in this process stems from the hypothesized ability
of reciprocal feedbacks between ecology and evolution to influence how populations respond
to environmental change. Nonetheless, our understanding of this important relationship is in
its infancy. Progress is hindered by the difficulty of manipulating rapid evolution in field
populations, limited molecular resources to understand adaptation, and the inherent difficulty
of quantifying how the effects of evolution on ecological dynamics feed-back to affect
subsequent evolutionary change. My recent research work uses orchard populations of D.
melanogaster as a model system to understand how eco-evolutionary dynamics influence
adaptation to a seasonally changing environment. The work explores the population dynamic
consequences of manipulating fly evolution in tree-scale field mesocosms with an innovative
offspring replacement methodology. Parallel experimental manipulations quantify the
importance of temperature and density as drivers of rapid evolution. Utilizing the strengths
of D. melanogaster, the phenotypes, and genomic regions that underlie the adaptive response
to these and other seasonally changing factors are identified and evaluated for functional
significance