Data and R Markdown files for: Estimating the capacity of Chamaecrista fasciculata for adaptation to change in precipitation

Adaptation through natural selection may be the only means by which small
and fragmented plant populations will persist through present day
environmental change. A population’s additive genetic variance for fitness
(VA(W)) represents its immediate capacity to adapt to the environment in
which it exists. We evaluated this property for a population of the annual
legume Chamaecrista fasciculata through a quantitative genetic experiment
in the tallgrass prairie region of the Midwest USA, where changing climate
is predicted to include more variability in rainfall. To reduce incident
rainfall, relative to controls receiving ambient rain, we deployed rain
exclusion shelters. We found significant VA(W) in both treatments. We also
detected a significant genotype-by-treatment interaction for fitness which
suggests that the genetic basis of the response to natural selection will
differ depending on precipitation. For the trait specific leaf area, we
detected maladaptive phenotypic plasticity and an interaction between
genotype and environment. Selection for thicker leaves was detected with
increased precipitation. These results indicate capacity of this
population of C. fasciculata to adapt in situ to environmental change.