Wallace and Darwin came up with natural selection independently. Darwin read a paper by Wallace, a quick sketch of the theory, and decided to step up publication of On the Origin of the Species to avoid getting scooped. If Darwin had plagiarized Wallace, he would have had to have written the book in about 15 minutes.
In fact, Wallace and Darwin became good friends and close collaborators. If Darwin had plagiarized Wallace, Wallace certainly didn't seem to think he had.
Yes, yes... that what it was. Darwin said so himself I'm sure...
It wasn’t just Wallace, it appears he plagiarized the work of a number of scientists, to include Edward Blyth and Thomas Malthus. And it would appear that poor old Wallace went to his grave never knowing that his so-called friend ripped him off.