Study Questions - speciation
Readings - chapter 13
1) New species can form by gradual, progressive genomic incompatibility. Provide an example.
2) However, it is also possible that certain genes have a disproportionate effect on reproductive isolation - such as coevolved, epistatic alleles. Explain.
3) Selection can cause phenotypic divergence, and we could envision simplistic cases where these differences correlate directly with reproduction (selection for radical difference in body sizes would isolate subpopulations as a mechanical barrier). Describe the differences in stickleback ecotypes in this context.
4) Hybrization can create a new species if the new combined genotypes are stabilized, somehow, by reproductive isolation. How have alpine moths become reproductively isolated? How about H. heurippa? Be sure to provide data.
5) Hybridization and backcrossing are powerful ways of both introducing new variation and also identifying gnes that might be responsible, either indirectly (through their arrangment) or directly (through their effects). Explain.
6) Polyploidy can also create new species. Describe the mechanisms of auto and allopolyploidy. Aside from immediately establishing a reproductively isolated population, polyploidy can also introduce beneficial, adaptive variation. Explain how.
7) Unfortunately, polyploidy also typically causes deleterious effects. Explain.
8) So, how can a lineage take advantage of ebenfits while reducing or eliminating the negative effects.