Age: 37
Occupation: Scientist, New York Stem Cell Foundation
No one has yet been able to clone a human being, but Egli has come the closest. One of the few scientists in the world adept at nuclear transfer — the technique that generated Dolly the sheep, the first cloned mammal — Egli has cloned human skin cells. Why bother, given the ethical and biological challenges of creating mini-mes? Because the technique could generate embryonic stem cells from patients that could be used to treat diabetes, heart disease and Alzheimer's.