Asian black bear
Biologically and morphologically, Asiatic black bears represent the beginning of the arboreal specializations attained by sloth bears and sun bears. Asiatic black bears have karyotypes nearly identical to those of the five other ursine bears, and, as is typical in the genus, they have 74 chromosomes. From an evolutionary perspective, Asiatic black bears are the least changed of Old World bears, with certain scientists arguing that it is likely that all other lineages of ursine bear stem from this species. Scientists have proposed that Asiatic black bears are either a surviving, albeit modified, form of "Ursus etruscus", specifically the early, small variety of the Middle Villafranchian (Upper Pliocene to Lower Pleistocene) or a larger form of "Ursus minimus", an extinct species that arose 4,000,000 years ago. With the exception of the age of the bones, it is often difficult to distinguish the remains of "Ursus minimus" with those of modern Asiatic black bears.
Sun bear
The main predator of sun bears throughout its range by far is man. Commercial poaching of bears for the wildlife trade is a considerable threat in most countries. During surveys in Kalimantan between 1994 and 1997, interviewees admitted to hunting sun bears and indicated that sun bear meat is eaten by indigenous people in several areas in Kalimantan. High consumption of bear parts was reported to occur where Japanese or Korean expatriate employees of timber companies created a temporary demand. Traditional Chinese medicine (TCM) shops in Sarawak and Sabah offered sun bear gallbladders. Several confiscated sun bears indicated that live bears are also in demand for the pet trade.