The evidence of common ancestry is based on study of
three parameters; fossils record, homologies of various
organisms, and study of biogeography. Fossils record determines the similarity and differences of
bones as well as shells of different organisms over a given period of time. On the
other hand, studying of homologies involves assessment of mitochondrial DNA and
other proteins with an aim of finding similarity from one organism to
another. Finally, Biogeography is the
assessment of how continental drift might have separated organisms which had
got common ancestry and they were living together.
