>>20095773>>20095741Real world cloning, not anime/sci-fi world cloning, is done by extracting an Egg from a host mother, and converting it into an embryo. During this process, Mew's DNA would have been spliced and reconfigured.
The embryo is then re-injected into the host mother's womb, and develops into a zygote which then becomes an embryo which then becomes a fetus which then becomes a baby.
And thus the genes are pulled from the mother, into the mother, and the offspring is a clone.
In this case, the genes of the clone were modified from the mother's DNA - however, no second contributor was ever used besides SCIENCE!!!!, so Mew is still the sole parent and Mewtwo is still technically, that mew. Just heavily mutated.
Mutations are normal in genetics, after all. No fetus is ever born on earth without undergoing small amounts of genetic mutation.