The
cheetah (Acinonyx jubatus) is an atypical member of the cat family (Felidae)
that is unique in its speed, while lacking strong climbing
abilities. The species is the only living member of the genus
Acinonyx. It is the fastest land animal, reaching speeds between 112
and 120 km/h (70 and 75 mph) in short bursts covering distances up
to 460 m (1,510 ft), and has the ability to accelerate from 0 to
103 km/h (64 mph) in three seconds, faster than most supercars.
The cheetah has unusually low
genetic variability and a very low sperm count and motility, and
deformed flagella. Skin grafts between unrelated cheetahs illustrate
this point in that there is no rejection of the donor skin. It is
thought that the species went through a prolonged period of
inbreeding following a genetic bottleneck during the last ice age.
It probably evolved in Africa during the Miocene epoch (26 million
to 7.5 million years ago), before migrating to Asia. New research by
a team led by Warren Johnson and Stephen O'Brien of the Laboratory
of Genomic Diversity (National Cancer Institute in Frederick,
Maryland, United States) has recently placed the last common
ancestor of all existing species as living in Asia 11 million years
ago, which may lead to revision and refinement of existing ideas
about cheetah evolution. Now-extinct species include: Acinonyx
pardinensis (Pliocene epoch), much larger than the modern cheetah
and found in Europe, India, and China; Acinonyx intermedius
(mid-Pleistocene period), found over the same range. The extinct
genus Miracinonyx was extremely cheetah-like, but recent DNA
analysis has shown that Miracinonyx inexpectatus, Miracinonyx
studeri, and Miracinonyx trumani (early to late Pleistocene epoch),
found in North America and called the "North American cheetah" are
not true cheetahs, instead being close relatives to the cougar.
The
cheetah (Acinonyx jubatus) is an atypical member of the cat family (Felidae)
that is unique in its speed, while lacking strong climbing
abilities. The species is the only living member of the genus
Acinonyx. It is the fastest land animal, reaching speeds between 112
and 120 km/h (70 and 75 mph) in short bursts covering distances up
to 460 m (1,510 ft), and has the ability to accelerate from 0 to
103 km/h (64 mph) in three seconds, faster than most supercars.
