April review for F1000

This month we have found some good papers.  We decided to first review a paper that is very much in Mark's field of interest - what factors determine species invasion success.  This paper provides some evidence as to whether greater phenotypic plasticity of invasives is important. 


 AM Davidson, M Jennions, AB Nicotra (2011) Do invasive species show higher phenotypic plasticity than native species and, if so, is it adaptive? A meta-analysis. Ecol Lett 2011 Apr 14 4:419-31
DOI 10.1111/j.1461-0248.2011.01596.x

Our Review: Parry H, Lonsdale M: 2011. F1000.com/9268957 
Another review of this paper is also available at the above link, by Hao Wang and Mark Lewis of the University of Alberta, Canada. 


What are the determinants of success in invasive species? Tonnes of wood pulp have been expended in proposing predictors of invasion success, such as morphology, taxonomic relatedness and propagule pressure, which might help us to screen out dangerous species before it is too late. One hypothesis put forward is that the greater phenotypic plasticity of invaders, compared with natives, determines the success of invasive species (1}. This study provides evidence to support this hypothesis through a comparative analysis, but fails to find support for the related hypothesis, that such phenotypic plasticity results in a fitness advantage for invasives {1}. Using a meta-analysis of 75 invasive and non-invasive species pairs, the study finds that invasive species show greater phenotypic plasticity than their non-invasive congeners. Strangely, however, this greater plasticity is only rarely associated with greater fitness. In fact, the study finds that, when resources are limiting, non-invasive species respond better.

Where does this leave us? The study has shown the greater plasticity of invasives compared with natives. However, the study could not relate this to fitness, and so concludes that the benefits of plasticity to the invader will be context sensitive. This latter conclusion highlights the difficulty of predicting invasion success on the basis of biological attributes alone - it is the interaction of those attributes with the environment that will determine invasion success.

References:
{1} Richards et al. Ecol Lett 2006, 9:981-93