BILD 3 Lecture 7: 1-30-17 lecture notes 7
Document Summary
The evolution of increased prezygotic isolation in order to reduce the production of unfit hybrids is reinforcement. The evolution of diversity from a common ancestor upon introduction to new environmental opportunities. One of the world"s great showcases of adaptive radiation. Is enabling researchers to identify specific genes involved in speciation. Perhaps only rarely as a result of direct selection against hybridization. Sympatric speciation appears to require the simultaneous evolution of trait divergence and assortative mating. Behavioral ecologists distinguish between proximate and ultimate causes of behavior. The immediate stimulus and mechanism for the behavior. How the behavior contributes to survival and reproduction. Sequence of unlearned, innate behaviors that is unchangeable. A fap is triggered by an external sensory stimulus. In male stickleback fish, the stimulus for attack behavior is the red underside of an intruder. As long as some red occurs, the attack response is stimulated. Proximate and ultimate causes for the fap attack behavior in male stickleback fish.
