There's a subtle point involved here that I'll try to explain, and I hope you catch my explanation:
A real scientist does NOT "use evidence to support his theory". That would mean that he dreamed up his theory, then he went around observing the world and nature, and he wrote down and took pictures of things he saw that supported his theory, and he ignored anything that didn't support it. This is exactly how science does NOT work. Anybody who operates that way is laughed out of science and you never hear about him again.
The way science works is exactly the opposite: The curious investigator observes the world and the things around him. He sees how things actually work. That's the 'evidence'. Eventually he comes to the point where he's ready to build a theory of WHY or HOW things work the way they actually do.
The theory is built to explain the evidence. The evidence is not used to support a theory. And after the theory is offered, the next step is to test the theory and see if it's worth anything.
Wegener observed that m<span>ountain chains are continuous across continents, and he learned that similar fossils have been found on different continents. When he saw these and other facts, he eventually offered the theory of continental drift, to EXPLAIN the evidence.
