Quick! Who was Snuppy?
And why should you care?
Snuppy, the world's first cloned dog, was born April 23, 2005, in South Korea. Like all cloned animals, Snuppy was created using reproductive cloning technology, or nuclear transfer. It's done by transferring genetic material from the nucleus of a cell belonging to a donor animal to an egg whose nucleus, and thus genetic material, has been removed.
The technology, according to the Human Genome Project, isn't perfect cloning. The genetic material in the nucleus isn't the only source of genetic material, but it's a pretty big chunk of it.
Snuppy wasn't the first mammal to be cloned. That distinction goes to Dolly the sheep.
Cloning of animals goes further back, though – to 1952, when a tadpole was cloned.
Lots of things have been cloned, in different ways. The process doesn't always result in a genetic "twin"; embryonic stem cells, for example, have been harvested to attempt to treat diseases.
For today, we're going to stick to animal cloning, starting with Snuppy and looking at a few other examples through the years. Click through the photos to see.
(For an interesting read on the business of cloning dogs, take a look at "Dog, Inc.," by John Woestendiek.)