Evidences of Evolution

1. Evidences of Evolution Honors Biology Jefferson County High School J. Harper CLE 3210.5.4

2. 1. Fossil Evidence • A fossil is the preserved remains or imprint of an organism that lived many years ago. • Fossil evidence shows the changes between species that lived in the past and those alive today. • Scientists have used fossils to show the similarities between species that are extinct and their modern relatives.

5. 2. Comparative Morphology • Many species have a common anatomical (physical) structure. • The branch of science in which structures of living things are compared to understand their development among species is called comparative morphology. • (“Morph”- form, “ology” – study of) • Bone structures and body parts can be divided into two distinct categories.

6. Body Part Categories A. Analogous Structures- serve the same purpose in different species but evolved independently. In other words, these structures did not evolve from the same structures in a common ancestor. • Example: Butterflies, bats & birds wings B. Homologous Structures- are similar body parts found in different species. These body parts provide evidence that each of the different organisms developed from a common ancestor. • Example: Forelimb bone structure

8. 3. Embryology • An embryo is: a developing organism at a stage prior to birth or hatching. • Embryology is the study of living things before birth. Many organisms are very similar in appearance and have common features as embryos but vary significantly as adults. • These similarities provide evidence for evolution from common ancestors.

10. 4. Biochemical Evidence • Organisms that look similar today are believed to have a more recent common ancestor than do organisms that look very different. However, we do not rely solely on outward appearances. • By looking at similarities in DNA using gel electrophoresis, scientists can tell how closely related two organisms are by comparing the number of base pairs they have in common. • Example: Many organisms contain a red blood cell protein called hemoglobin. The amino acid sequence for this protein in humans is almost identical to the sequence for this protein in gorillas. They differ by only one amino acid.

11. Newspaper Article Assignment • Get in groups of 3-4. • Design a newspaper article about the evidences of evolution. Your article should tell the public about the evidence for evolution. Summarize what you have learned today. • Make a creative title for your newspaper. • Write a creative, catchy headline for your article. • You must have at least one picture in your newspaper. It should have a caption! • Your newspaper should have the date and the writer’s names on it. • Make it colorful!