A cheetah known as Chewbaaka has helped scientists time-travel through that species’ long, complex history, even providing some clues about how the big cats became the world’s fastest land animals.

A cheetah known as Chewbaaka has helped scientists time-travel through that species’ long, complex history, even providing some clues about how the big cats became the world’s fastest land animals.

Chewbaaka, rescued as a 10-day-old orphan in Namibia, became an “ambassador” animal for the Cheetah Conservation Fund there. (His name is a variation of the “Star Wars” character’s.) He died five years ago at the advanced age of 16 — twice the life span of the average cheetah in the wild — but not before geneticists drew his blood. Along with blood samples from six other cheetahs from Namibia and East Africa, his has now been used to sequence the species’ complete genome — its full set of chromosomes.

With their spotted coats and black “teardrop” facial markings, cheetahs are a favorite of tourists on photographic safaris. The animals race across the African savanna at speeds close to 60 miles per hour because of their unique physiology: elongated legs, aerodynamic skull, enlarged adrenal glands and heart muscles, and claws that grip the earth like football cleats. Considered critically endangered, cheetahs number only about 10,000 today, with most living in southern and eastern Africa.

What the genomic analysis reveals is not encouraging: The cheetah has less than 5 percent of the genomic diversity of other wild cats, a level much lower than even inbred domestic dogs and cats and the lowest among the 30 mammals whose genomes have been sequenced. Genetic diversity in an animal is determined by variation in enzyme genes inherited by an animal’s two parents and is critical to its healthy reproduction and immunity to disease.

Scientists began to suspect that the cheetah was “genetically monotonous” several decades ago. Surgical skin grafts done experimentally among unrelated cheetahs were tolerated without the normal rate of tissue rejection, as if all the animals were identical twins. Cheetahs in captivity were difficult to breed and had unusually high mortality rates among the cubs. And the animals showed high vulnerability to outbreaks of disease.

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