Lab-meeting on August 28 2011: Space, time and evolution

It is time for a new semester of intellectually challenging and exciting lab-meetings in order to sharpen our brains. The first one this semester deals with a "new" idéa which turns out to not to be that new at all, although it is the first time it has been explicitly developed. It is a paper by Australian herpetologist Richard Shine and co-workers in the journal PNAS, entitled: "An evolutionary process that assembles phenotypes through space rather than through time". The paper is published through the "Open Access"-option and can be easily be downloaded here.

Time and place as usual: "Argumentet" on Wednesday, August 31 2011 (unless that room is occupied). Fika volunteers are welcome. Below you can find the abstract.

An evolutionary process that assembles phenotypes through space rather than through time

1. Richard Shine^a,¹,
2. Gregory P. Brown^a, and
3. Benjamin L. Phillips^b

+ Author Affiliations

1. ^aSchool of Biological Sciences A08, University of Sydney, Sydney, NSW 2006, Australia; and
2. ^bSchool of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia

Abstract

In classical evolutionary theory, traits evolve because they facilitate organismal survival and/or reproduction. We discuss a different type of evolutionary mechanism that relies upon differential dispersal. Traits that enhance rates of dispersal inevitably accumulate at expanding range edges, and assortative mating between fast-dispersing individuals at the invasion front results in an evolutionary increase in dispersal rates in successive generations. This cumulative process (which we dub “spatial sorting”) generates novel phenotypes that are adept at rapid dispersal, irrespective of how the underlying genes affect an organism's survival or its reproductive success. Although the concept is not original with us, its revolutionary implications for evolutionary theory have been overlooked. A range of biological phenomena (e.g., acceleration of invasion fronts, insular flightlessness, preadaptation) may have evolved via spatial sorting as well as (or rather than) by natural selection, and this evolutionary mechanism warrants further study.

• colonization
• evolution
• spatial disequilibrium
• nonadaptive evolution