The Evolution of Reproductive Isolation as a Correlated Character Under Sympatric Conditions: Experimental Evidence

Abstract

A set of experiments is described that tests the general hypothesis that sympatric speciation is genetically feasible whenever reproductive isolation evolves indirectly as a correlated character. We specifically test the hypothesis that disruptive selection on habitat preference can lead to sympatric speciation when individuals mate locally within their selected habitat. Drosophila melanogaster was used as a model system. A 35-generation experiment using a complex habitat maze led to complete reproductive isolation between subpopulations using different spatiotemporal habitats. The reproductive isolation that developed over the course of the experiment was a result ofoffspring returning to mate in the habitat type selected by their parents, i.e., a gradual breakdown in migration between habitats.

Local variation and parallel evolution: morphological and genetic diversity across a species complex of neotropical crater lake cichlid fishes

“…It requires that multiple factors occur in concert: strong trade-offs in efficiencies to maximize fitness (Levins 1962); spatial and/or ecological conditions that maintain polymorphism and frequency-dependent selection (e.g. Udovic 1980;Otto et al 2008); the evolution of reproductive isolation between ecologically dissimilar types (Maynard Smith 1966;Rice & Salt 1990;Kirkpatrick & Ravigné 2002); and a mechanism for ecologically relevant mate choice (Higashi et al 1999;Takimoto et al 2000). Conversely, under the forces of natural selection, parallel evolution may be rather likely (Orr 2005) and disruptive selection rather common (Martin & Pfennig 2009).…”

An Individual-Based Modeling Approach to Investigate Sympatric Speciation via Specialized Resource Usage

“…Moreover, this comparison revealed the significant role of reproductive isolation and assortative mating caused by disruptive selection pressure exerted by the exploitation of different resources in sympatric speciation [37] Our unique modeling approach does not simply assume that individuals are involved in foraging and mating activities; it also comprises all other possible considerations, which might play an important role from evolutionary perspective. Applying this complex modeling approach we highlighted significant indicators of behavioral modifications caused by preferential resource use.…”

“…In 1963, Mayr argued against sympatric speciation and proposed that allopatric speciation is the prevalent type of speciation [2]. Since then many investigators such as Smith (1966) (by his simple model [34]), and most significantly Rice (by his empirical and theoretical studies) [35] [36] [37] have striven to prove that disruptive selection could frequently lead to sympatric speciation. Today, thanks to a large number of empirical observations and mathematical models, it is generally acknowledged that sympatric speciation is theoretically possible and has occurred in nature.…”

Experimental macroevolution

“…It can readily be produced as a consequence of selection for habitat choice. Drosophila populations were offered a series of binary choices between environmental cues, such as odours and light [51]. Each sequence of preferences led to a different oviposition chamber, but the progeny was discarded from all except two.…”