Understanding the effect of competition during adaptive radiations: an integrated model of phenotypic and species diversification

ARÍSTIDE, LEANDRO; MORLON, HÉLÈNE

Montpellier

Congreso; II Joint Congress on Evolutionary Biology; 2018

European Society for Evolutionary Biology, American Society of Naturalists, Society for the Study of Evolution, Society of Systematic Biologists

Over large temporal scales, the evolutionary processresults in changes in the two main dimensions of biological diversity:phenotypic disparity and species number. Understanding how different macroevolutionary patternsarise from this underlying process is a long-standing goal for biology. In thissense, a large body of work has pointed to the role that biotic factors mayplay over macroevolutionary time. Moreover, both theory and empirical evidence support the ideathat ecological interactions (e.g. competition) can drive both trait evolutionand species origination, mechanistically linking the diversification ofphenotypes with that of species (for example, in adaptive radiations). However,despite recent developments, macroevolutionary models to studydiversification that explicitly encapsulate ecological mechanisms are generally lacking.Moreover, all phylogenetic tools share the potential shortcomingof assuming that the evolutionary process consists of two unlinkedsub-processes (i.e. speciation-extinction and trait evolution) that can bestudied separately. Here, with the aim ofunderstanding how competition affects diversification dynamics, we introduce a unified phylogenetic model of?evolutionary radiation? in which lineages and traits diversify together,representing the expectations ofdiversification by ecological speciation through character displacement. Byusing simulations, we explore how competition influences evolutionary rates andthe features of the resulting trees and trait values. Additionally, we studythe effect of extinction on the diversification process when competition ispresent, and whether our model can recreate observed patterns in clades wherecompetition is believed to have driven diversification (i.e. adaptiveradiations). Our model represents a step forward towards the development ofintegrated and ecologically explicit phylogenetic models of diversification.