Cloning Extinct Animals An intriguing question involves the cloning of animals that are extinct. In order to accomplish this feat, one must have access to preserved frozen animal cells as a source for the genetic material to be cloned. In 1999, a preserved frozen woolly mammoth was discovered in Siberia, giving rise to the hope that this great creature might one day live again. However, the animal*s body had been subject to repeated cycles of freezing and thawing over many years, disrupting the structure of its genetic material so that it is unsuitable for interspecies nuclear transfer. Scientists at the Australian Museum have attempted to clone the Tasmanian tiger, which became extinct in the 1930's. The source of animal tissue in this case is a tiger that was preserved in alcohol in 1866; however, DNA analysis has shown that there was extensive damage to the genetic material of this specimen, making successful cloning unlikely. In Spain, the recently extinct bucardo, a mountain goat, has been the subject of cloning experiments. Scientists at the Agricultural Research Service in Zaragoza prepared frozen tissue from the last surviving animal of this species of mountain goat, which had been relegated to extinction due to loss of its natural habitat and poaching. In 1999, successful interspecies transfer of embryos of the bucardo using a domestic goat as a surrogate mother raised hopes that the bucardo might be cloned using this same surrogate species.
North American Wild Horses Considered the symbol of the freedom of the AmericanWest, mustangs roam prairies, in addition to isolated areas along the East Coast and in the Midwest. In the early twentieth century, the federal government ordered the extermination of mustangs. Velma "Wild Horse Annie" Johnston lobbied Congress in the 1950's to stop wild horse slaughters. Congress passed theWild Free-Roaming Horse and Burro Act in 1971 to protect wild horses under the jurisdiction of the Bureau of Land Management (BLM). The Wild Horse Act of 1999 assured federal protection for a feral horse herd in Missouri. Although wild horses are romanticized in books and movies, realistically they pose problems such as uncontrolled population increase, encroachment on urban areas, and destruction of rural landscapes. They also are at risk from animal predators, microscopic diseases, and human poachers. Droughts and wildfires in the late twentieth century depleted food sources, resulting in many mustangs starving. Roundups by helicopters drive wild horses toward government corrals, where they are fed and offered for adoption to the public. Approximately forty-six thousand wild horses roamed the AmericanWest in 1999, and seven thousand were adopted. Such dispersal, however, is controversial. Some of the mustangs are actually sold for slaughter because horse meat is a popular food in Asia and Europe, due to concerns about bovine spongiform encephalopathy (mad cow disease). Critics of the BLM suggest that agency will inadvertently cause the extinction of America's wild horses.
