Camelus bactrianus

The Bactrian camel (Camelus bactrianus) is a large, even-toed ungulate native to the steppes of Central Asia. The Bactrian camel has two humps on its back, in contrast to the single-humped dromedary camel. Its population of two million exists mainly in the domesticated form. Their name comes from the ancient historical region of Bactria. Domesticated Bactrian camels have served as pack animals in inner Asia since ancient times. With its tolerance for cold, drought, and high altitudes, it enabled the travel of caravans on the Silk Road. A small number of feral Bactrian camels still roam the Mangystau Province of southwest Kazakhstan and the Nubra Valley in India. Bactrian camels, whether domesticated or feral, are a separate species from the wild Bactrian camel which is the only truly wild (as opposed to feral) species of camel in the world. The Bactrian camel shares the genus Camelus with the dromedary (C. dromedarius) and the wild Bactrian camel (C. ferus). The Bactrian camel belongs to the family Camelidae. The ancient Greek philosopher Aristotle was the first to describe the species of Camelus: in his 4th-century-BC History of Animals he identified the one-humped Arabian camel and the two-humped Bactrian camel. The Bactrian camel was given its current binomial name Camelus bactrianus by Swedish zoologist Carl Linnaeus in his 1758 publication Systema Naturae. In 2007, Peng Cui (of the Chinese Academy of Sciences) and colleagues carried out a phylogenetic study of the evolutionary relationships between the two tribes of Camelidae: Camelini — consisting of the three Camelus species (the study considered the wild Bactrian camel as a subspecies of the Bactrian camel) — and Lamini — consisting of the alpaca (Vicugna pacos), the guanaco (Lama guanicoe), the llama (L. glama) and the vicuña (V. vicugna). The study revealed that the two tribes had diverged 25 million years ago (early Miocene), notably earlier than what had been previously estimated from North American fossils. Speciation began first in Lamini as the alpaca came into existence 10 million years ago (late Pleistocene). Nearly two million years later, the Bactrian camel and the dromedary emerged as two independent species. The Bactrian camel and the dromedary often interbreed to produce fertile offspring. Where the ranges of the two species overlap, such as in northern Punjab, Iran and Afghanistan, the phenotypic differences between them tend to decrease as a result of extensive crossbreeding between them. The fertility of their hybrid has given rise to speculation that the Bactrian camel and the dromedary should be merged into a single species with two varieties. However, a 1994 analysis of the mitochondrial cytochrome b gene revealed that the species display 10.3% divergence in their sequences. The wild Bactrian camel (Camelus ferus) was first described by Nikolay Przhevalsky in the late 19th century and has now been established as a distinct species from the Bactrian camel (Camelus bactrianus). In particular, a population of wild Bactrian camel has been discovered to live within a part of the Gashun Gobi region of the Gobi Desert. This population is distinct from domesticated herds both in genetic makeup and in behavior. As many as three regions in the genetic makeup are distinctly different from Bactrian camels, with up to a 3% difference in the base genetic code. However, with so few wild camels, what the natural genetic diversity within a population would have been is not clear.