Poopville, the fall and rise

He noticed that the species that inhabited islands that were distant from one another usually tended to differ more than those that lived on islands that were closer together. Thus Darwin came to the conclusion that a single ancestral species might have given rise to two daughter species over a long period of time. He then began to construct an ever-expanding family tree of animals. This is were he ran into his first problem, If there has been long term patterns of change in the features of life on earth, what forces could account for them? Darwin eventually came up with this answer, since different forms, arise through the appearance of heritable changes, tend to reproduce at different rates; some w...