Episodic processes, invasion and faunal mosaics in evolutionary and ecological time

Authors: Hoberg, Eric; BROOKS, DANIEL - University Of Nebraska

Submitted to: Cambridge University Press
Publication Type: Book / Chapter
Publication Acceptance Date: 6/1/2012
Publication Date: 2/1/2013
Citation: Hoberg, E.P., Brooks, D. 2013. Episodic processes, invasion and faunal mosaics in evolutionary and ecological time. In: Rohde, K., editor. The Balance of Nature and Human Impact. Cambridge, UK: Cambridge University Press. p. 199-214.

Interpretive Summary: The mode and pace of biological invasions have shifted over the course of human history such that few corners of the planet are now free of the impacts from exotic introduced species. The character of human-mediated invasion differs to some degree relative to process in natural systems, not only due to the intentional or accidental aspect, but also the degree to which long-range introductions typify these events leading to colonization, establishment, amplification and dissemination. Human-related drivers increasingly influence invasion and the distribution of invasive species, with attendant threats across a matrix linking environments, economies and societies. This study explored and identified the primary mechanisms involved in invasion for freeliving species and ther associated parasites, and demonstrated the link and generalities between events in deep historical time with those unfolding in contemporary ecosystems. Conclusions of this study which address geographic invasion are of relevance in understanding emerging infectious diseases for animals and people, and of direct importance for animal health, wildlife biology and conservation biology in identifying the drivers and outcomes for ecological change on local, regional and global scales.

Technical Abstract: Episodes of ecological perturbation and faunal turnover represent crises for global biodiversity and have occurred periodically across Earth history on a continuum linking deep evolutionary and shallow ecological time. Major extinction events and biodiversity crises across the 540 milion years of the Phanerozoic are equated with periods of maximum ecological disruption associated with geological, oceanographic and atmospheric (climatological) mechanisms which have influenced patterns and processes for diversification (dispersal and isolation), species diversity, community and faunal structure, turnover, and distribution on global to regional and landscape scales. Episodic or punctuated events set the stage for patterns of diversification and faunal associations downstream for extended periods of time. In essence, the cascading effects of ecological disruption may canalize faunal structure, eliminating evolutionary potential through differential extinction events, but concurrently may heighten faunal mixing and interchange through breakdown in ecological isolation during biotic expansion and geographic colonization. Paradoxically, ecological crises may also be precursors for subsequent radiation and diversification in taxa which have persisted through events of maximal ecological perturbations, and elevated rates for speciation are often linked to periods of rapid climatological and environmental change. These processes and their influence on faunal structure and diversity are equivalent in evolutionary and ecological time and thus can serve as analogues for understanding and predicting the general outcomes of invasion and range shifts in contemporary communities and faunas.