Objective: How do adaptations affect fitness and lead to natural selection?

Phenotype = physical traits Expression of the organism’s genotype TALK IT OVER: What are the phenotypes of the salamander? (DO NOT WRITE DOWN)

Partner Talk: Compare boxes 1, 2, & 3. Which mouse has a higher survival rate? Why?  An organism’s phenotype will determine whether or not they survive.  Natural selection acts directly on organism’s phenotype

 Inherited trait that is important for an organism's survival  Affect fitness = ability to survive and reproduce in its environment

 Limited resources = competition  Genetic variation means some more fit than others  Survival of the fittest – individuals with the best adaptations will survive and pass them on

 Directional Selection: favors extremes  Stabilizing Selection: favors average (most common)  Disruptive Selection: favors extremes at both ends  * Over time can lead to speciation!!!

At the bottom of today’s notes: In 3 complete sentences summarize the main idea of today’s lesson. (highlight and number your periods)