Dogs come in all sorts of shapes and sizes, while house cats are relatively homogeneous. How come?
Turkeys on poultry farms are artificially inseminated. Why can’t they mate like those in the wild do?
Consider an island where a species of bird relies on the nuts of a particular type of tree for food. As a result of a prolonged drought, the trees on the island start producing nuts that are much smaller than normal, and with thicker and harder shells. What do you think will happen to the birds? Be specific. What type of selection will result: directional, stabilizing, or disruptive?
A vestigial structure is one of marginal, if any importance to an organism. Vestigial structures are historical remnants of structures that had important functions in ancestors. Provide six examples of vestigial structures, and briefly explain why each is considered so.