Temporal variation can facilitate niche evolution in harsh sink environments
Authored by RD Holt, M Barfield, R Gomulkiewicz
Date Published: 2004
DOI: 10.1086/422343
Sponsors:
United States National Institutes of Health (NIH)
United States National Science Foundation (NSF)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
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Abstract
We examine the impact of temporal variation on adaptive evolution in
``sink{''} environments, where a species encounters conditions outside
its niche. Sink populations persist because of recurrent immigration
from sources. Prior studies have highlighted the importance of
demographic constraints on adaptive evolution in sinks and revealed that
adaptation is less likely in harsher sinks. We examine two complementary
models of population and evolutionary dynamics in sinks: a
continuous-state quantitative-genetics model and an individual-based
model. In the former, genetic variance is fixed; in the latter, genetic
variance varies because of mutation, drift, and sampling. In both
models, a population in a constant harsh sink environment can exist in
alternative states: local maladaptation ( phenotype comparable to
immigrants from the source) or adaptation ( phenotype near the local
optimum). Temporal variation permits transitions between these states.
We show that moderate amounts of temporal variation can facilitate
adaptive evolution in sinks, permitting niche evolution, particularly
for slow or autocorrelated variation. Such patterns of temporal
variation may particularly pertain to sinks caused by biotic
interactions ( e. g., predation). Our results are relevant to the
evolutionary dynamics of species' ranges, the fate of exotic invasive
species, and the evolutionary emergence of infectious diseases into
novel hosts.
Tags
selection
Populations
Consequences
Density-dependence
Local adaptation
Changing environment
Immigration
Adaptive evolution
Black-hole sink
Species borders