Biology 156 26 Mar 2001
Evolutionary Ecology Bob Podolsky
Week 11. Evolutionary morphology (part 2)
Study guide
After the module on phenotypic plasticity, you should be able to:
Lecture 9.1. Definitions and examples of plasticity
- Describe criteria necessary to show that plasticity is an adaptive feature of an organism
- Apply the criteria needed to demonstrate evolution by natural selection to the concept of demonstrating the evolution of plasticity
- Define and distinguish the terms polymorphism and polyphenism
- Describe Palumbi's initial observations about differences in sponge morphology among environments that varied in wave exposure
- Propose three hypotheses (different processes) that could underlie this pattern
- Describe experiments that Palumbi carried out to test one of these hypotheses, including the sponge characteristics he examined and his methods of measurement
- Explain his predictions about changes in sponge morphology and his graphical results
- Use Palumbi's data to examine his hypothesis that there are also costs to maintaining stiff/strong tissue
- Explain why Palumbi's results give support for a tradeoff that might select for the maintenance of morphological plasticity in individual sponges
- Describe Lively's initial observations about the spatial distribution of barnacles with two different morphologies
- Propose three hypotheses to explain this pattern he observed
- Explain the experiments that Lively used to test one hypothesis for how different barnacle morphologies are induced
- Use the total of Lively's data to evaluate whether tradeoffs exist that could select for morphological plasticity
- Review the results of Seeley for the evolution of snail morphology in response to crab predation, and give an alternative hypothesis proposed by Trussell to explain Seeley's results
- Explain why Trussell's data tend to support Seeley's hypothesis about the evolution of snail shells