Highly Variable Spread Rates in Replicated Biological Invasions: Fundamental Limits to Predictability

Abstract

Limits to Invasion Predictions Using mathematical models linked to experiments on laboratory insect populations, Melbourne and Hastings (p. 1536 ) show that current models seriously underestimate variability in spatial spread. Genetic founder effects resulting from small population sizes are probably responsible for the surprising increase in variability and for increased uncertainty of ecological forecasts. Thus, even without exogenous sources of variability such as weather, fundamental uncertainties arise biologically from inherent differences among individuals and small population sizes.