Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence
Article first published online: 23 FEB 2014
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Ecology and Evolution
Volume 4, Issue 7, pages 899–910, April 2014
How to Cite
Ecology and Evolution 2014; 4(7):899–910
- Issue published online: 7 APR 2014
- Article first published online: 23 FEB 2014
- Manuscript Accepted: 10 JAN 2014
- Manuscript Revised: 7 JAN 2014
- Manuscript Received: 2 DEC 2013
- USDA Hatch
- USDA-NRI. Grant Number: 2006-03645
- European Research Council. Grant Number: 281422
- ANR projects SCION. Grant Number: ANR-08-PEXT-03
- EVORANGE. Grant Number: ANR-08-PEXT-11
- National Science Foundation. Grant Number: IOS-1238885
- critical transitions;
- functional traits;
- invasive species;
- Phalaris arundinacea ;
Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions.