On April 23, Stochastic Morphometry project welcomed Professor David Polly who presented a talk “Continuity and discontinuity: functional trade-offs, mobile adaptive peaks, and paths through morphospace”. Professor David Polly is a Fellow of the American Association for the Advancement of Sciences (AAAS) and Chair of Department of Earth and Atmospheric Sciences at Indiana University, USA. Throughout his career he has used GMM as the main tool to investigate a variety of macroevolutionary questions, mainly regarding ecomorphology and integration/modularity.
Abstract of the presentation: The idea of an adaptive peak or adaptive landscape has usually been viewed as highly mobile and context-dependent, but at the same time the mechanisms by which a lineage may cross from one adaptive peak to another has been viewed as a central problem in evolutionary biology since the early 20th century. Today the adaptive peak concept has been used to develop statistical models like Ornstein-Uhlenbeck (OH) and multi-peak to infer modes of evolution and the shapes of adaptive landscapes from empirical distributions of traits on phylogenetic trees. The algorithms of most existing statistical models assume (explicitly or implicitly) that adaptive peaks are non-mobile because that assumption makes it easier to compare the fits of competing models. In this talk I will present a statistical model I helped developed to estimate the relative contributions of competing functional demands to the evolution of complex morphological traits. Like many statistical models of evolution, this model is based on the adaptive peak concept but differs in interesting ways from most implementations of multi-peak adaptive landscape model in that the peak in the new model is inherently mobile and assumes there are no obvious fitness valleys to cross.