Wednesday, October 19, 2011
The Cheetah: An Example of Genetic Bottleneck
Today, the small remaining cheetah population remaining in Africa faces many pressures which threaten the continuing existence of the species. Cheetahs first evolved in North America over 8 million years ago and dispersed around the globe over time, evolving into many different species and subspecies. 12,000 years ago during the last glacial maximum, large glaciers caused cheetahs to become locally extinct everywhere except for Africa. However, the few surviving cheetahs all shared similar genetics, creating a genetic bottleneck within the population. Genetic bottlenecks threaten a population due to the many complications of inbreeding, which include more common defects and less resistance to disease. The idea of cheetahs experiencing a genetic bottleneck has been tested scientifically. Results from testing cheetah DNA indicate that the cheetah did in fact experience a genetic bottleneck 12,000 years ago (Menotti –Raymond and O’Brien, 1993). In addition to the challenges posed by low genetic diversity, the cheetah also faces pressures from an increasingly fragmented habitat, and competition for food from both humans and other large cats.
Work cited:
Menotti-Raymond, M. "Dating the Genetic Bottleneck of the African Cheetah." Proceedings of the National Academy of Sciences 90.8 (1993): 3172-176. Web. .
Work Referenced:
Gugliotta, Guy. "Rare Breed | Science & Nature | Smithsonian Magazine." History, Travel, Arts, Science, People, Places | Smithsonian Magazine. Web. 19 Oct. 2011. .
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