Divergent - This type of evolution often occurs when closely related species diversify to new habitats. On a large scale, divergent evolution is responsible for the creation of the current diversity of life on earth from the first living cells. On a smaller scale, it is responsible for the evolution of humans and apes from a common primate ancestor.
Convergent - Convergent evolution causes difficulties in fields of study such as comparative anatomy. Convergent evolution takes place when species of different ancestry begin to share analogous traits because of a shared environment or other selection pressure. For example, whales and fish have some similar characteristics since both had to evolve methods of moving through the same medium: water.
Parallel evolution - Parallel evolution occurs when two species evolve independently of each other, maintaining the same level of similarity. Parallel evolution usually occurs between unrelated species that do not occupy the same or similar niches in a given habitat.
The equation that relates the angle of the polarization and the intensity of ligth transmitted is I=Io*cos²(x), where I is the intensity of the incident light, Io is the intensity of the transmitted light, and x is the angle of polarization. The fraction of incident light will be I/Io, so the answer in given by cos²(37) = 0.6378
