1. INTRODUCTION TO EVOLUTION
AP BIOLOGY
MR. ORNDORFF
FEB. 2004

2. Special Creation vs. Evolution
Species distinct and created separately by a divine being.
Earth is thousands of years old. Humans present at original creation.
Must be accepted on faith (religion).
Species are all related through “descent with modification.”
Earth is billions of years old. Humans appeared late in earth’s history.
Must be testable and supported with evidence (science).

3. Microevolution vs. macroevolution
Small-scale evolution (change within a species).
Examples:
Darwin’s Finches
Pesticide resistant insects
Grand-scale evolution (mass extinction and creation of new species)
Examples:
Eu- from prokaryotes
Extinction of dinosaurs
Adaptive radiation of mammals

4. Evidence for macroevolution
Biogeography (no placental mammals in Australia).
Fossil Record (vertebrate skeletons)
(Whale Fossils-
Comparative anatomy (homologous structures and vestigial organs).
Comparative embryology.
(Embryology Film Clip-
Molecular biology (DNA and proteins).

5. Fossil formation (Fig. 22.2)

6. Homologous structures (Fig. 22.9)

7. Molecular data and vertebrate evolution (Fig. 22.11)

8. Mechanisms for Evolution
Lamarck ( )
Organisms “feel a need” to adapt.
Use and disuse idea (e.g. blacksmith biceps and giraffe neck).
Inheritance of acquired characteristics theory.
Darwin ( )
Individuals vary (e.g. pigeons and dogs).
Like tends to beget like.
Limited resources allow few offspring to survive.
Theory of natural selection.

9. Subtleties of Natural Selection
Individual organisms do not evolve. A population is the smallest unit that evolves.
Natural selection acts only on hereditable variations (i.e. genetically controlled traits).
Natural selection acts differently as environmental factors vary from place to place and time to time.

10. Natural selection in action (Fig. 22.7)