Fossils
Fossils give us an idea of how the bones of organisms have changed overtime.Examples of fossils are: Imprints, cast, molds, mineralized bones, and Relatively intact organisms found preserved in ice, tar or amber.The way we determine how old a fossil is by relative and absolute Absolute dating is using radioactive isotopes to determine fossil age.Relative dating is determine by the rock layer the fossil is found in
Comparitive anatomy
Comparative anatomy compares the similarities between limbs of different organisms.There are two types of comparative anatomy homologous and analogous structures.Homologous Structures – structures in different organisms that are similar in origin and structure but may differ in function. Analogous Structures - body parts that are similar in function only, but do not come from a common evolutionary ancestor.
Vestigial structures
Vestigial structures are structures that are present but not needed. Examples of Vestigial are the human tailbone and appendix, human ear muscles, eyes of a blind cave salamander, and wings of an ostrich. Organisms that have vestigial structure usally have common ancestry.
Biochemistry
Biochemistry helps us determine, by using DNA and RNA, how closley related two organisms are. It also tells use they come from a common ancestor. An example is chimpanzee and an human who are 98.6 precent similar.
Embryological Development
Embryological Development - a comparison of the early stages of embryonic development may show similarities that suggest a common ancestor. Example are, early embryos of fish, reptiles, birds, and humans closely resemble one another. As the embryos develop we can start to see the distinct features of the organism.
