Cloning is the process of creating an organism with the exact same nuclear DNA as another. The type of cloning most commonly used in the fight against animal extinction is called reproductive cloning. Scientists use somatic cell nuclear transfer (aka: SCNT) in the cloning of animals, a process that involves genetically copying (cloning) an embryo and then transferring it to a female host to grow and be "born." [Click here for a diagram.] Animals cloned using this technique are not technically identical because even though their nuclear/chromosomal DNA is the same, some genetic material comes from the mitochondria in the cytoplasm of the embryo.
Efforts have been made to "bring back" extinct species, but so far no one has been successful. For DNA to be successfully extracted, the organism must be dead less than five days. That certainly rules out the dinosaurs. Other cloning attempts have been made when there are only a few of a species left, but in most of these instances the clone was born only to die after a few days. The first endangered wild animal clone was born in 2001-- a rare ox called a guar-- but it died withink 48 hours. Italian scientists successfully cloned a mouflon (an endangered wild sheep) in 2001 and it's still alive!
Endangered species cloning isn't the entire solution to the animal-extinction problem, though. Even if scientists can clone a few organisms to raise the populations of the endangered species, these creatures are still dying out. Their habitats are being destroyed, poachers are killing them, and their genetic diversity is dwindling. Betty Dressler, director of the Audubon Institure Center for Research of Endangered Species (aka: AICRES), comments, "I don't believe one thing will save these species. This technology will help form a safety net, but habitat conservation is critical." |
