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Saving lives has always been an important mission of science.Now science, and indeed all society,is **cing a new dilemma: whether or not to try and save more lives through human cloning.

The first cloning experiments in the 1950s involved frogs and toads. It was not until 1997 that scientists successfully coloned the first mammal, the now world-**mous sheep known as Dolly. Cloning techniques have continued to improve since then, and
today there are clloned mice, salmon, and cattle.

Some scientists want to apply the methods used in cloning animals to produce skin, organs, and other body parts for human. One of these methods involves taking adult cells from the brain or blood and growing the into new tissues. Another, more complex, technique takes embryo cells and develops them into a wide variety of cell types and tissues. It is this planned use of human embryos that has resulted in controversy and criticism.