UVA BIOL 2200 Lesson 7 - Speciation and Hybridization

University:
University of Virginia
Course:
BIOL 2200 | Introduction to Biology II: Organisms & Evolution
Academic year:

2023
Views:

14

Pages:

4
Author:

Zoe C.

Lecture 7: Speciation & Hybridization (1/31) polyploidy as a speciation mechanism polyploidy is a successful speciation mechanism in plants because: • it happens nearly instantaneously • it provides higher genetic diversity • it leads to reduced inbreeding depression sticklebacks and speciation • limnetic sticklebacks feed on plankton in open water on lakes • benthic sticklebacks feed in invertebrates near the lake bottom adaptation, acclimation, and speciation • adaptation: natural selection in response to environment leads to increased frequency of phenotype in the population over time • local adaptation: species exhibit phenotypes that differ due to local conditions • • could lead to speciation over time acclimation: a physiological response to the environment leads to change in individual phenotype during a single generation hybridization and speciation • hybridization: when reproductive isolation between two species breaks down • hybrids less fit → reinforcement • • individuals that hybridize have fewer offspring • reproductive isolation increases hybrids more fit → fusion • individuals that hybridize have an equal number or more of offspring • reproductive isolation decreases • hybrids fit more in a specific time/place • hybridization is limited • small hybrid zones or variable conditions • hybrid production continues ] stability evolution and speciation • speciation is the result of reproductive isolation • evolutionary processes that lead to reproductive isolation: • • natural selection • genetic drift • mutation gene flow reduces reproductive isolation rate of speciation punctuated equilibrium does punctuated equilibrium suggest that natural selection is not the primary mechanism behind evolution?