Ecological speciation involves the evolution of reproductive isolation (RI) as a by-product of adaptation to different selective environments. Parallel patterns of non-random mating by environment type provide strong evidence that ecological speciation has occurred. The processes involved in the origins of RI are more difficult to detect however. One mechanism involves the correlated evolution of mating preferences and sexually selected traits. I developed a conceptual model for detecting RI under various scenarios of mate preference evolution. The model predicts that RI will not evolve if preferences are evolutionarily constrained relative to the preferred traits, but is detectable as long as preferences evolve in parallel. I then applied this framework to an empirical system with populations of guppies (Poecilia reticulata) adapted to low- and high-predation environments. I measured female mate preferences for male colour and size; traits which are divergent between the two environment types. Preference functions for colour also diverged in the predicted direction. The parallel pattern of preference divergence suggests that divergent natural selection from predators may be contributing to RI between guppy populations.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82432 |
| Date | January 2005 |
| Creators | Schwartz, Amy K. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002209294, proquestno: AAIMR12547, Theses scanned by UMI/ProQuest. |
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