You've definitely heard of Charles Darwin, but does the name Alfred Wallace ring a bell? Perhaps it should. The paper that shook up the scientific world in 1858 was co-authored by the two men, but Wallace's name faded into obscurity shortly after its publication. Wallace independently conceived the theory of natural selection, and wrote about his findings to his mentor, Charles Darwin. Darwin had reached the same conclusions a few years earlier, but had done nothing with his findings. The two put their nearly identical research together to publish a co-authored paper on the subject. One year after the paper was published, Darwin published his famous book "On the Origin of Species," which led to his fame. Perhaps Wallace's greatest contribution to the conversation around natural selection is the question, "Why do we find this animal in this place?"