A. Seppänen, K. Parvinen and J.D. Nagy (2012)|
Evolution of Dispersal in American Pika (Ochotona princeps) Metapopulations
Evolutionary Ecology Research 14, 1-29
Question: How might global climate change (GCC) affect American
pika (Ochotona princeps) metapopulation dynamics in the Great Basin,
and how would such effects impact evolutionary dynamics of dispersal? Back to all articles
Mathematical methods: A structured, semi-discrete, mechanistic metapopulation
model in which patch age is the structuring variable. We apply adaptive dynamics
for the evolutionary analysis and derive an invasion fitness proxy for this
Key assumptions: Global climate change potentially alters probability
of patch extinction, dispersal costs, mortality and fecundity. Births and
immigration occur at discrete points in time. Deaths and emigration occur
continuously over time. We model ``average'' patch dynamics.
Results: Potentially viable metapopulations nevertheless can be
destined for extinction via evolutionary suicide driven by climatic forcing.
Specifically, selection can drive down dispersal rates in viable metapopulations,
degrading colonization rates and increasing extinction rates to the point
where the metapopulation crashes.
Conclusions: Exclusive reliance on ecological dynamics without this
evolutionary perspective would miss the phenomenon identified here. This
result arises in realistic ranges of parameters and therefore generates a
testable hypothesis with potential applications to long-term metapopulation