5 Concluding remarks
Although there is a growing literature assessing hypotheses related to
the Baldwin effect, Plasticity-First hypothesis, and the Bogert
effect[5,10,21,111], no papers have systematically compared and
contrasted, theoretically or experimentally, how these expectations
differ across the three parameters of environmental change (rate of
change, variation, autocorrelation). Here we pose a framework yielding
testable hypotheses to encourage both experimental and theoretical
research that takes into account simultaneous variation in plasticity
and genetics in response to changing environments.
There are increasing reports of phenotypic and genotypic data from
natural populations exposed to changing environmental
regimes[41,112,113]. They allow direct assessment of genetic and
plastic adaptive processes over time and under different environmental
scenarios. Therefore, the time is ripe to reassess our understanding of
the relative roles of phenotypic evolution by selection and plasticity.
Here, we have introduced an integrative framework that delineates null
hypotheses for when and how much plasticity might be employed for
adaptive evolution and persistence under realistic types of
environmental change. With more explicit theories and field measurements
of how the rate of change, variability, and temporal autocorrelation of
the environment impact the mechanisms of evolutionary responses, we may
reach a deeper understanding of species responses in the Anthropocene.