The need to integrate phylogeny to improve models of community structure and dynamics

Phylogenetic signal in predator–prey body-size relationships

Russell E. Naisbit,Patrik Kehrli,Rudolf P. Rohr,and Louis-Félix Bersier

 Ecology,Volume 92, Issue 12 (December 2011)

Body mass affects metabolism, life history, and population abundance. It frequently sets bounds in food chain.  
                                      
Based on a collection of topological food webs, Ulrich Brose and colleagues presented a general relationship between the body mass of predators and their prey. Brose analysed how mean predator–prey body-mass ratios differed among habitats and predator metabolic categories.

Here the researchers show that the general body-mass relationship conceals significant variation associated with both predator and prey phylogeny. They say Major-axis regressions between the log body mass of predators and prey differed among taxonomic groups. The global pattern for Kingdom Animalia had slope >1, but phyla and classes varied, and several had slopes significantly <1. The researchers contend that predator–prey body-mass ratio can therefore decrease or increase with increasing body mass, depending on the taxon considered.

The researchers also found a significant phylogenetic signal in analyses of prey body-mass range for predators and predator body-mass range for prey, with stronger signal in the former.

The researchers sign off with the following words” Besides providing insights into how characteristics of trophic interactions evolve, our results emphasize the need to integrate phylogeny to improve models of community structure and dynamics or to achieve a metabolic theory of food-web ecology.”