Experiment is the Ultimate Test

The ultimate test of a scientific hypothesis is experiment. Experiment specifically means that you don't just wait for nature to do something, and passively observe it and see what it correlates with. You go in there and do something. You manipulate. You change something, in a systematic way, and compare the result with a 'control' that lacks the change, or you compare it with a different change.

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If your hypothesis is that the non-random survival of random genetic variation has important evolutionary consequences, the experimental test of the hypothesis would have to be a deliberate human intervention. Go in and manipulate which variant survives and which doesn't. Go in there and choose, as a human breeder, which kinds of individuals get to reproduce. And that, of course, is artificial selection. Artificial selection is not just an analogy for natural selection. Artificial selection constitutes a true experimental - as opposed to observational - test of the hypothesis that selection causes evolutionary change.

Richard Dawkins, The Greatest Show on Earth: The Evidence for Evolution (2010-08-24)

• experimentation
• scientific method