| A | B |
|---|
| Organic evolution | the process of species changing over time |
| Fossil | Any trace or remains of an organism that has been preserved by natural processes. |
| Amber | A hard, yellow, transparent material formed by the hardening of tree resin, in which insects become trapped. |
| Ice | Allows whole organisms to be preserved for thousands of years in cold Artic regions. |
| Fossil Bones | Under some conditions, the hard, mineral parts of animals such as shells, bones, and teeth can be preserved. |
| Petrification | The process by which the remains of an organism turn to stone by replacing original substances with minerals from the water in which the organism dies. |
| Mold | When the remains of an organism decay, but the shape is preserved in the rock as a hollow form. |
| Cast | When a mold fills with minerals and hardens into rock in the form of the original organism. |
| Comparative Anatomy | The study of structural similarities and differences among living things which may show an evolutionary relationship. |
| Homologous Structures | When parts of different organisms have similar structures that serve different functions (bat wing and human arm), they are said to share a common ancestor. |
| Analogous Structures | When parts of different organisms have different structures that serve similar functions (bird wing and insect wing), they are said to have evolved along different lines. |
| Vestigial Structures | Remnants of structures that were functional in ancestral forms, but in modern forms are smaller and serve no function. |
| Comparative Embryology | The longer 2 different species share similar embryonic forms, the closer the evolutionary link. |
| Comparative Biochemistry | The more similar 2 different species DNA is, or the proteins derived from the DNA, the closer the evolutionary link. |
