Evolutionary Biology - Darwin's Theory of Co-Evolution

Darwin was the one that really emphasized in his studies of natural selection, that competition and dominance was how species were able to pass their genes on. Darwin himself knew that competition wasn't the only way that plants and animals interacted. He also knew that they cooperated but his writings were most relevant in the field of evolution with this competition model. Over time, some scientists, and I'm going to talk about Lynn Margulis, who was an evolutionary biologist as well, came up with the theory of endosymbiosis. We are not just a human being. Our guts alone have about two pounds of bacteria in them that do all the digesting of our food.