HS-LS4-2

SCUSD NGSS Curriculum Guide
 * HS-LS4-2: ** **Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.** [Clarification Statement: Emphasis is on using evidence to explain the influence each of the four factors has on number of organisms, behaviors, morphology, or physiology in terms of ability to compete for limited resources and subsequent survival of individuals and adaptation of species. Examples of evidence could include mathematical models such as simple distribution graphs and proportional reasoning.] [Assessment Boundary: Assessment does not include other mechanisms of evolution, such as genetic drift, gene flow through migration, and co-evolution.]

Science Background for the Teacher:
[overview of relevant science background for teacher]
 * Behaviors evolve


 * **Emphasize**: Fitness can be measured by number of offspring that live long enough to reproduce
 * Variation already exist
 * Not all features are adaptations

Key Vocabulary:

 * Evolution || genetic variation || mutation || competition ||
 * survival || proliferation || Survival of the Fittest || Adaptation ||
 * Fitness || Population || Species || Trait ||

Possible Assessments (formative and/or summative):
**Preassessment**; "Is it Fitter?" from Uncovering Student Ideas in Science.

Key Student Activity:
**Predator Adaptation Lab:** Each student is given a different feeding utensil. There are 4 different types of food on a colored background. Students may use their feeding utensil to pick up food. Those that pick up the most food are more likely to survive - those that do not pick up food die.

Present students with data, and make predictions based on data. After completing previous activity, students are able to predict preferred food sources based on beak shape.

Key Teacher Demo/Activity:
- The Grant's study of beaks and Galapagos finches - data? - Different forms of selection - show the graphs and give examples of directional, stabilizing and disruptive selection.

Common Student Misconceptions:

 * Fitness means how well an organism fits its environment
 * If we evolved from monkeys, why are there still monkeys?
 * Mutations are all bad

Things to Avoid/Correct:

 * References to "god", "creation"

====Other Resources (text, video, simulations, activities, models, etc..): ====
 * www.scilinks.org
 * ensi.org
 * Understanding Evolution Website (good for teacher background)
 * http://ats.doit.wisc.edu/biology/ev/ns/t2.htm
 * Handouts (source? please attach file): Evolution webquest, Darwin's theory, STHS Biology predator adaptation lab, A Step in Speciation - Spotted Salamanders
 * Crash Course - 10 minute video on Speciationhttp://www.youtube.com/watch?v=2oKlKmrbLoU&list=SP3EED4C1D684D3ADF