Theoretical Perspectives on the Statics and Dynamics of Species' Borders in Patchy Environments
Authored by Michael Barfield, Robert D Holt
Date Published: 2011
DOI: 10.1086/661784
Sponsors:
United States National Institutes of Health (NIH)
United States National Science Foundation (NSF)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
Understanding range limits is a fundamental problem in ecology and
evolutionary biology. In 1963, Mayr argued that ``contaminating{''} gene
flow from central populations constrained adaptation in marginal
populations, preventing range expansion, while in 1984, Bradshaw
suggested that absence of genetic variation prevented species from
occurring everywhere. Understanding stability of range boundaries
requires unraveling the interplay of demography, gene flow, and
evolution of populations in concrete landscape settings. We walk through
a set of interrelated spatial scenarios that illustrate interesting
complexities of this interplay. To motivate our individual-based model
results, we consider a hypothetical zooplankter in a landscape of
discrete water bodies coupled by dispersal. We examine how patterns of
dispersal influence adaptation in sink habitats where conditions are
outside the species' niche. The likelihood of observing niche evolution
(and thus range expansion) over any given timescale depends on (1) the
degree of initial maladaptation; (2) pattern (pulsed vs. continuous, uni- vs. bidirectional), timing (juvenile vs. adult), and rate of
dispersal (and hence population size); (3) mutation rate; (4) sexuality;
and (5) the degree of heterogeneity in the occupied range. We also show
how the genetic architecture of polygenic adaptation is influenced by
the interplay of selection and dispersal in heterogeneous landscapes.
Tags
Climate-change
Natural-selection
Gene flow
Local adaptation
Interspecific competition
Ecological consequences
Black-hole sink
Individual-based simulations
Geographic range limits
Niche
evolution