Hello, my name is Charles Darwin, and today we are going to talk about the development of my theory of natural selection and its impact on biology and the scientific community.

In the early 1800s geologists and paleontologists who had been examining strata and fossils had compiled significant evidence that the Earth had a long history in which many species had existed, changed, and in some cases, gone extinct. Scientists at this time were puzzled by the mechanism of this change.

Before the publication of On the Origin of Species there were many competing theories on the cause of this evolution. Some scientists believed it was due to a trait inherent to life which called organisms to transform from lower single-cell forms to higher multicellular forms, or that evolution was predeterminate like the development of an embryo.