Comparative Anatomy Homologous, Analogous & Vestigial Structures These type structures can be used to determine the evolutionary relationship between organisms

Homologous Structures These structures have a similar developmental beginning in the embryo but the final structure in the adult organism has a different function. These organisms are related Analogous Structures These structures have a different developmental beginning in the embryo but the final structure in the adult organism has a similar function. These organisms are not related

Homologous Structures

Vestigial Structures These are structure that are leftovers from the past. Most have little or no really purpose in the organism. Vestigial structures in humans: Hair Finger and toe nails Arrector pili muscles “ Goose bumps” Ear pinna Appendix (partially vestigial) Coccyx - tail bones Little toe Wisdom teeth

Comparative Embryology Related organisms commonly look alike when they are developing as an embryo.

Comparative Biochemistry You can compare the chemicals organism have in their body to see how closely they are related. Two of the most important chemicals to compare are: Enzymes found in the body DNA found in the cells