The Evolutionary History of Cheetahs
In most mammals, any two members of the same species tend to be fairly similar. For example, when looking at enzymes, humans rate at about 70% identical. This rate is good enough to ensure similarity while also maintaining genetic diversity. In cheetahs however, they all rate at about 97% identical. This guarantees similarity among the species, but at the same time, eliminates genetic diversity. Experts believe that a bottleneck (as described on the previous page) caused the cheetahs to become so similar to each other. They also believe that this bottleneck occurred about 10,000 years ago, and was caused by a natural disaster. Because so few cheetahs were left, they were eventually forced to reproduce with their close family members in order to keep the species alive. In genetics, this sort of thing is called inbreeding. This is an issue because inbreeding often times causes offspring to inherit the same bad recessive alleles, resulting in disease and birth defects.
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The Problem with the CheetahDue to the cheetah population's low genetic diversity, the modern cheetah faces a wide variety of problems. Most cheetahs today have poor sperm quality, focal palatine erosion, kinked tails and are all susceptible to the same diseases. Genetic diversity is important because it allows a population to have more resistance to drastic environment changes and help prevent mass epidemics which could lead to extinction.
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Focal Palatine Erosion
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The Natural Solution
On the bright side though, there is a natural solution to this issue that requires little to no human intervention. It has been discovered that female cheetahs mate with multiple males rather than just one. They also tend to mate with males from far off areas. Because of this, most litters consist primarily of half-brothers and half-sisters. This is good because it ensures more genetic diversity within litters. More cheetahs will have the opportunity to pass on their genes, so more genes will be preserved and not lost over time. This method of mating also helps to prevent infanticide. Infanticide is common among big cat species, and is when a male kills a female's cubs if they are not his own. However, because female cheetahs mate with so many males, it is hard for the males to tell which cub(s) are his and which aren't, which helps to keep them from killing any.
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