Chapter 18.5, Problem 1HYEW

Scientists have cloned a number of animal species, including mice, dogs, cats, horses, and cows. Could the technology of cloning be used to bring back extinct species? In principle, yes, provided that perfectly preserved DNA of the extinct species is available. Such DNA could be transferred to an egg from a closely related, living species, and the egg implanted in a surrogate mother of that species.

For example, researchers have suggested that it might be possible to clone a woolly mammoth, using an elephant surrogate mother and DNA extracted from 20,000-year-old mammoths found frozen beneath the Siberian tundra.

Most scientists, however, believe that any DNA recovered from a fossil mammoth would be far too degraded for use in cloning, and synthesizing an entire mammoth genome (its sequence is now almost fully known) is beyond the capabilities of current technology. The odds of success might be greater for another proposed project, which would use DNA from a preserved museum specimen to revive the Tasmanian tiger, an Australian mammal that has been extinct for only 70 years. If cloning recently extinct species proves to be possible, do you think it would be a good idea?

If Extinct Species Can Be Revived by Cloning?