The geological record does not support Darwin’s theory because there are no intermediate species found in fossils and sometimes groups display abrupt modifications. However, this can be the result of changes in the earth’s surface, unfitting conditions for fossil formation, the destruction of existing fossils, and the lack of discovery of fossils. Darwin uses these possibilities to argue against the naturalists, saying that there is not enough knowledge about the history of earth to draw conclusions on …show more content…
Over long periods of time, newer and better adapted species gradually replace older ones, which become extinct. All species are modified, creating increasingly complex and developed organisms that form new species which are connect to their ancestors through intermediate species. Darwin cannot fully explain what unfavorable conditions cause species to go extinct, but this extinction is definitely a result of the struggle for existence, as well as a necessary part of natural selection. The fiercest competition is usually between similar species, resulting in the eventual extinction of one of them, after which it is improbable that another similar species would come into existence. Darwin also argues that although natural selection does not act on ecosystems, it is possible for species around the world to change at the same time. “Parallel succession” is supported by geological evidence of similar fossils of the same period found in similar limestone formations in different places. However, later changes in these species’ behavior or environment can lead to further natural selection and formation of new species. Changes in one species can also affect changes in another. Natural selection often results in families of species that have been formed from a single parent species over time, the relationship of which can be determined through fossil records. Related