Some evolutionary biologists have argued that trait evolution is constrained in some way, so that many traits are NOT optimally adapted. Give a real or hypothetical example of a trait whose evolution has depended on phylogenetic contingency rather than on adaptation. For each of the following situations, answer the question about adaptation based on the phylogenetic information given as well as the descriptions of the traits. To practice interpreting and drawing phylogenies, also draw one or several phylogenetic trees to illustrates each situation.
Finches make up one monophyletic group, warblers make up a different monophyletic group.
Consider four different monophyletic groups of frogs. Within each of four groups of frogs, some species climb trees have the ends of their toes expanded into structures that look like suction cups, while other species do not climb trees do not have expanded toes. Studies of bog habitats suggest that such leaves may be functional in conserving water during times of the year when the bog is frozen. Kangaroos, kangaroo rats, deer, and ostriches live in habitats where as a result of predation and habitat structure, animals that can run or jump fast in a straight line survive best. However, when this is graphed for the frog, bird, and mammal that vocalize, there is no apparent trend.