Hans METZ – Geometries of Macro- respectively Meso-Evolution: two lectures
Nov 22, 2007 | 16:15Lecture Hall 1, Biocenter, University of Vienna, Austria
Organized by: Hans METZ ( Section Theoretical Biology, Institute of Biology, Leiden University)
Lecture 1: Attempts to contribute to a postmodern synthesis: explorations in the interface between macro- and meso-evolution
Evo-Devo and adaptive dynamics (AD) are two main postmodern contributions to the evolutionary synthesis. Evo-Devo contributes to a predictive understanding of the evolutionary process by (1) telling how easily different changes of morphologcal (s.l.) patterns are generated, and (2) outlining the selective pressures caused by the need for a good, stable, developmental integration. AD explores the consequences of the changes in the finer features of the fitness landscape caused by the community dynamics. AD techniques mainly use local properties of the fitness landscape. Hence AD can only deal with meso-evolutionary timescales. From a larger perspective the low-dimensional fitness landscapes occurring in most AD studies can be seen as surfaces at the top of ridges in a much higher dimensional landscape of potential morphologies, with the abyss around the ridges created by the lack of a proper development or functioning. The location of the ridges and abysses is grossly the same for the variety of environmental conditions that can be set by the community dynamics in the considered time windows.
Lecture 2: Meso-evolutionary predictions derivable from the interplay between ecology and evolution
Adaptive Dynamics is a framework geared towards making the transition from micro-evolution to macro-evolution based on a time scale separation approximation. This assumption allows defining the fitness of a mutant as the rate constant of initial exponential growth of the mutant population in the environment created by the attractor of the resident community dynamics.
This definition makes that all resident types have fitness zero. If in addition it is assumed that mutational steps are small, evolution can be visualised as an uphill walk in a fitness landscape that keeps changing as a direct result of the evolution it engenders. One of the intriguing consequences from studying the singular points of the resulting dynamical systems is the existence of a fairly ubiquitous type of singularity that engenders adaptive diversification (including potentially speciation). Another type of singular points are so-called Evolutionarily Stable Strategies, characterised by the fact that in the environment created by such a strategy no mutants has positive fitness. Contrary to what is suggested by their name ESSs may still repel meso-evolutionarily; attracting ESSs are called CSSs.
Hans Metz has been full professor of Mathematical Biology in Leiden, The Netherlands, since 1986. He obtained his MA from Leiden University in 1971 (cum laude), and his PhD from Leiden University in 1981. His work lies in Mathematical Biology, especially Adaptive Dynamics. Since 1996 he is group leader and senior adviser of the Adaptive Dynamics Network - Evolution and Ecology Program of the IIASA (Laxenburg, Austria). From 2006 to 2007 he was a visiting professor at the Ecole Normale Superieure and Paris VI. From 2006 to 2007 he was a visiting professor at the University of Helsinki.