Animal clones

Have you ever had a burger so tasty you wished you could eat it all over again?

With the way that cloning research is going, your wish may someday come true. The United States government has declared that it's safe to consume food that made from cloned animals. The decision has aroused debates about human health, animal rights, and ethical issues.

Clones are similar to identical twins. They are exact genetic copies of each other. The difference is that twins turn up without involving scientists and are born at the same time. Clones are created in the laboratory and could be born years apart. Until now, scientists have cloned 11 kinds of animals, including sheep, cows, pigs, mice, and horses.

Dolly the sheep was the first mammal to be cloned from the DNA of an adult. Here she is with her first-born lamb, Bonnie.

Scientists who study cloning envisage an unlimited supply of disease-resistant livestock, record-setting racehorses, and animals of species that would otherwise have gone extinct.

As cloning techniques are being refined continuously and even more cloned animals are being created, some people are worried. So far, few cloning attempts are successful. The animals that do survive tend to die young.

Cloning raises a variety of issues. Is it a good idea to let people clone a favourite pet? What if cloning could revive the dinosaurs? What would happen if scientists ever figure out how to clone people? Should we be worried? Or, should we be excited about the advanced technology?