Butler argument had been that everything that Darwin has written has been said before. He attacked Darwin on many points as I discussed in an earlier post, but I would like to concentrate on his theories of Use and Disuse. Butler made the point that Evolution was not necessarily Darwinism. Darwinism included evolution but not vice versa. The theory of use and disuse was first proposed by Lamarck where he used their example of the giraffe. Lamarck also included in his theory spontaneous variation. Butler argued that there was little difference in the theories of Darwin and Lamarck except for the amount of influence of each part.
Lamarck believed that Use and Disuse was the primary means of evolution with a small part of it being due to spontaneous variation, whereas Darwin said spontaneous variation is the main reason behind Variation with use and disuse being secondary. This is not a small difference in the theory. It actually is a completely different theory and way of thinking compared to Lamarck. Darwin knew that Lamarck's Theory of Inheritance of Acquired Characteristics was wrong. We now know this because of experiments. We now know that changes that happened in an animals life aren’t passed on to there offspring. If you were to cut the tail off a dog like a Rottweiler, the offspring of the dog would still have a tail. We also now know that traits can only be passed on through genes, and genes cannot be affected by the environment. These and other examples show that Lamarck's theory does not explain evolution correctly. Lamarck has the pieces of the puzzle but he just couldn’t put it together. Darwin did and for that reason he is credited for his theories of evolution.