Human races are a. classes rooted in innate biological differences b. discrete categories into which all individuals can be easily assigned c. socially-constructed groups d. categories that appropriately represent the static nature of biological variation

Adaptive radiations can be a direct consequence of four of the following five factors. selectthe exception. a) vacant ecological niches b) genetic drift c) colonization of an isolated region that contains suitable habitat and few competitor species d) evolutionary innovation e) an adaptive radiation in a group of organisms (such as plants) that another group uses as food