Which of the following bears has the greatest amount of genetic diversity: Giant Panda, Brown Bear, Spectacled Bear, Polar Bear, or American Black Bear?

Please give evidence and website resources.

Diversity

Bears are a small group of mostly large mammals, with 8 species in 5 genera (Ursus, Tremarctos, Melursus, Helarctos, and Ailuropoda). Although Ursidae is not diverse, species in this family are widespread and culturally significant to human populations throughout their range. (Flynn, et al., 2005; Nowak, 1991; Vaughan, et al., 2000)

Geographic Range

Bears are found on all continents except Antarctica and Australia, but are primarily found throughout the northern hemisphere, historically occurring as far south as the Atlas Mountains of northwestern Africa, the Andes of South America, and the Sunda shelf region. This range has been reduced in historical times as a result of human persecution and habitat destruction. For example, brown bear (Ursus arctos) populations in the Atlas Mountains are thought to be extinct and their range has been significantly altered in North America and Europe. (Nowak, 1991; Pasitchniak-Arts, 1993; Vaughan, et al., 2000)

Biogeographic Regionsnearctic  native  palearctic  native  oriental  native  neotropical  native  

Habitat

Bears occur in nearly all terrestrial habitats throughout their range, from Arctic tundra and polar ice floes to tropical and temperate forests, mountains, grasslands, and deserts. Although some bear species occur in arid areas, proximity to water is important. Bears are most abundant and diverse in temperate and boreal regions. Most species are habitat generalists, changing preferred foods, activity patterns, and denning quarters with local conditions. Ailuropoda melanoleuca, however, is found primarily in the montane bamboo forests of southern China. (Chorn and Hoffman, 1978; DeMaster and Stirling, 1981; Fitzgerald and Krausman, 2002; Lariviere, 2001; Nowak, 1991; Pasitchniak-Arts, 1993; Vaughan, et al., 2000)

Explanation:

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.