There are good reasons why natural selection has become widely accepted as an explanation of evolutionary development. When applied to mammals and other large animals, it fits perfectly. But we cannot assume that all evolutionary steps arise from selection, particularly when looking at smaller animals.
Top 12 Quotes by John Tyler Bonner
When, as an undergraduate, I began experiments on these slime molds in 1940, only one other person, Kenneth Raper, was working on them at that time. In fact, he discovered the model species Dictyostelium discoideum, which is the species used in the majority of the experimental work today.