Evolutionary dynamics as a component of stage-structured matrix models: An example using Trillium grandiflorum
Authored by Michael Barfield, Robert D Holt, Tiffany M Knight
Date Published: 2008
DOI: 10.1086/589898
Sponsors:
United States National Science Foundation (NSF)
McKinley and Darbarker research fund
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Evolution by natural selection improves fitness and may therefore
influence population trajectories. Demographic matrix models are often
employed in conservation studies to project population dynamics, but
such analyses have not incorporated evolutionary dynamics. We project
evolutionarily informed population trajectories for a population of the
perennial plant Trillium grandiflorum, which is declining due to high
levels of herbivory by white-tailed deer. Individuals with later
flowering times are less often consumed, so there is selection on this
trait. We first incorporated selection analyses into a deterministic
matrix model in three ways ( corresponding to different methods that
have been used for analyzing evolution in structured populations).
Because it is not clear which of these methods works best for
stage-structured models, we compared each with a more realistic, individual-based model. Deterministic models using fitness averaged over
the phenotypic distribution gave trajectories that were similar to those
of the individual-based model, whereas the deterministic model using
fitness at the mean phenotype gave a much faster rate of evolution than
that which was observed. This illustrates that subtle differences in the
way in which one splices evolution into demographic models can have a
large effect on expected outcomes. This study demonstrates that, by
combining demographic and selection analyses, one can gauge the
potential relevance of evolution to population dynamics and persistence.
Tags
Reproductive success
Natural-selection
Biological-control
Conservation biology
Life-history evolution
Arabidopsis-thaliana
Quantitative genetics
Guppies poecilia-reticulata
Controlling
flowering time
Self-incompatibility