Fixity of species is a term which means all species remained unchanged throughout the history of the earth. This belief was the prominent belief in the western world prior to Charles Darwin work on evolution, the current accepted theory for specie diversity, in the mid-1800s. Most scientists who believed this view did so as an underlying assumption which was not encouraged by type of scientific reasoning. In this sense, these scientist did not actually support this belief system but allowed their ignorance of this topic to mislead their fundamental understanding of diversity. When various alternatives to fixity of species arose (such as Darwinian evolution), some scientist began to outspokenly support fixity of species.