Data from: Competitive history shapes rapid evolution in a seasonal climate

Eco-evolutionary dynamics will play a critical role in determining
species’ fates as climatic conditions change. Unfortunately, we have
little understanding of how rapid evolutionary responses to climate play
out when species are embedded in the competitive communities that
they inhabit in nature. We tested the effects of rapid evolution
in response to interspecific competition on subsequent ecological and
evolutionary trajectories in a seasonally changing climate using a
field-based evolution experiment with Drosophila melanogaster. Populations
of D. melanogaster were either exposed, or not exposed, to interspecific
competition with an invasive competitor, Zaprionus indianus, over the
summer. We then quantified these populations’ ecological trajectories
(abundances) and evolutionary trajectories (heritable phenotypic change)
when exposed to a cooling fall climate. We found that competition with Z.
indianus in the summer affected the subsequent evolutionary trajectory of
D. melanogaster populations in the fall, after all interspecific
competition had ceased. Specifically, flies with a history of
interspecific competition evolved under fall conditions to be larger, have
lower cold fecundity and faster development than flies without a history
of interspecific competition. Surprisingly, this divergent fall
evolutionary trajectory occurred in the absence of any detectible effect
of the summer competitive environment on phenotypic evolution over the
summer or population dynamics in the fall. This study demonstrates that
competitive interactions can leave a legacy that shapes evolutionary
responses to climate even after competition has ceased, and more broadly,
that evolution in response to one selective pressure can fundamentally
alter evolution in response to subsequent agents of selection.