Ruminants Are Hoofed Animals Such as Cattle and Sheep

Essay

Ruminants are hoofed animals such as cattle and sheep. Two categories of ruminants are browsers (leaf eaters) and grazers (grass eaters). Some biologists believe that the incisor arcade, that part of the mouth between the incisors, is shaped differently for browsers and grazers, and that might explain their food selection. The "curvature" of an incisor arcade is a measure of its shape, with large values indicating a long, thin mouth, and small values a shorter, wider mouth. The back-to-back stem plot below compares the curvatures of incisor arcades of a sample of species of browsers and grazers in the ruminant family. ​ (a) Briefly describe each of the two curvature distributions, browsers and grazers, noting any unusual features of the data. (b) The theory of some biologists is that browsers have thinner mouths because the browse plants frequently have thorns and spines; browsers have evolved to have thinner mouths to get beyond the thorns and spines to the food part of the plant. Is the data in the back-to-back stem plot consistent with this theory? What aspect of the data would you consider when answering this question?