It's interesting to contemplate the ethical question of whether a cloned human would be the sibling of, the child of -- or even the same being as -- the clonee.
More interesting is the question of whether -- being manmade -- a clone would even be human.
Most interesting of all is the question of whether cloning disproves God.
For Latter-day Saints, these are silly questions on many grounds:
• First, people ain't their bodies. The spirit animates the body, and the spirit is individual. From a religious point of view, the body is so much ash and dust. It doesn't determine one's nature or one's humanity. Only the individual, eternal spirit self can make the decisions and choices that determine one's humanity.
• In terms of spirituality and individuality, there is no difference between artificial cloning and natural cloning -- a relationship we call twins. We readily acknowledge that each of two twins born minutes apart are individuals. We even acknowledge that conjoined twins are individuals. It's remarkable that we then question whether each of two twins born 30 years apart are individuals. Surely they are, for they can choose individually and differently how they will live. Ironically, then, cloning may be the best evidence that man's spirit is individual and pre-existent.
• A person who raises his or her clone is called a "parent." Family relationships are born of behavior, not of genetics. Parents and their natural children share genetic characteristics in degrees that vary from child to child. As any adoptive parent will attest, the quality or nature of the DNA is irrelevant to the parent/child relationship. If you do the work, you get the title. End of discussion.
• Finally, there is only one valid argument against cloning: It's dangerous to children. The children of cloning are un-identical to their cloners, because cloned cells are degraded and aged forms of original cells. Giving a child something less than an optimal start -- when an optimal start is so easily accomplished -- is unethical.
There oughta be a law. Really.
-- The Practical Mormon