Dogs once covered the expanses of the great plains. their grazing made the grass more nutritious for the huge herds of bison, and they were preyed upon by a variety of snakes, raptors, and mammals. in fact, the black-footed ferret (now endangered) specialized in prairie dog predation. today, increases in housing and agricultural developments have eradicated many prairie dog towns. which of the following statements about prairie dogs is true? a) their realized niche has expanded. b) they have a competitive relationship with bison. c) they are probably a poor candidate for keystone species. d) their fundamental niche has been compromised. e) their fundamental niche has expanded.

(me out over the last several centuries, scientists have made the following broad observations while investigating several branches of the life sciences: -the fossil record shows that different types of organisms have existed at different times in earth's history. -many organisms have similar body structures that seem to be adapted to different ways of living in their environment. -organisms of different species often share similarities in stages of embryonic development. -many species share genetic similarities, and almost all organisms use the same basic building blocks to construct proteins. -often, the extent of two species' similarities can be predicted from their geographic closeness to each other. -a great deal of change has been observed among species that have experienced strong selective pressures through many generations. scientists have carefully considered and rigorously tested the observations listed above. when scientists offer a of these observations, they are making 1.) testable explanation, deductive explanation 2.) scientific interference, scientific law