> Humans have really long life cycles. Imagine how long an experiment that requires 2 generations of humans will take? And why is that a problem? More research

> Humans have really long life cycles. Imagine how long an experiment that requires 2 generations of humans will take? And why is that a problem? More research, more study material. In the two generations you'll have a cure+extra compared to a single dedicated animal study, that may not even work on humans. Loosely speaking.