EXAMPLES OF ADAPTATIONS

Types of Natural Selection 1. Directional Selection: Population moves to one extreme 2. Stabilizing Selection: Population moves to the middle 3. Disruptive Selection: Moves away from middle to both extremes

Natural Selection at Work: Rabbit Simulation Which rabbit would you expect to have the highest fitness in the arctic environment? In the equator environment? What happens when a friend is added? Why are they required for the population to change? How does this simulation mimic natural selection? How is it limited?

Determining Relatedness: Evidence for Evolution How can we tell how closely related organisms are using clues from evolution?? Comparative Anatomy Comparative Embryology Comparative Biochemistry

1. Comparative Anatomy: Phylogenetic Trees Shows how closely related different species are Use similarities in anatomy and structure Like family trees for organisms

1. Comparative Anatomy: Homologous Structures Definition: Characteristics that come from a common ancestor but are adapted to a different environment Why does this provide evidence for evolution??

Comparative Anatomy: Analogous Structures Definition: Structures that perform the same function but are not similar in structure

1. Comparative Anatomy: Vestigial Structures Definition: Structures that are inherited but no longer serve a purpose Why does this provide evidence for evolution?? Examples: human appendix, male nipples, human body hair, whale hip bone

Comparative Embryology During the development of an embryo (fetus), the longer they are similar, the more closely related the species are

Comparative Biochemistry The more similar the DNA and amino acid sequences of organisms, the more closely they are related