Evolutionary branching and speciation in a coevolutionary model of mutualistic interactions
Understanding speciation remains one of the fundamental challenges in evolutionary biology. It is currently believed that most species originated as a result of geographical isolation while the possibility of speciation in sympatry (i.e. without geographical separation) has often been dismissed. This standard wisdom was underpinned by the lack of a coherent theoretical framework for describing speciation in sympatry. The theory of adaptive dynamics has been applied to overcome this shortcoming. Adaptive dynamics allow for studying asexual phenotypic evolution driven by ecological interactions. One of the most interesting predictions of adaptive dynamics is the phenomenon of evolutionary branching. This process occurs when frequency-dependent selection splits an initially monomorphic population into two distinct phenotypic clusters. Evolutionary branching also arises in models of sexual populations and has therefore been suggested as a general paradigm for understanding sympatric speciation. The possibility for evolutionary branching is demonstrated in a number of classical models and for all fundamental types of ecological interactions. My project at IIASA focuses on a detailed classification of the coevolutionary dynamics that result in a model of mutualistic interactions.