Evolution WebQuest

Evolution Basics

• Definition of Evolution:

  • Evolution is the process through which modern organisms have descended from ancient ancestors.

• Mechanisms of Evolution:

  • Evolution occurs when a population experiences a change in genetics.

  • True or False: Only genetic differences that can be passed on are acted upon by evolution.

  • Example Scenarios:

    • Compare two changes in beetle populations: Circle the scenario that represents evolution and defend your reasoning.

• Basic Mechanisms for Evolutionary Change:

  1. Genetic Drift

     • A change in the frequency of genotypes due to chance events.

  2. Natural Selection

     • Organisms best adapted to their environment are more likely to reproduce and survive.

  3. Mutation

     • Sudden appearance of new genotypes in a population.

  4. Gene Flow

     • Change in genotype frequency due to the movement of individuals from one population to another.

• Genetic Variation:

  • Required for genetic drift and natural selection to take place.

  • Three sources: a. Mutationb. Migrationc. Sexual reproduction

• Mutations:

  • True or False: Changes in DNA are always harmful.

  • True or False: Only mutations in sex cells can be passed on.

  • True or False: External factors can cause mutations.

Gene Flow

• Gene flow is also known as migration and leads to changes in genetic frequency due to movement.

• Genetic Drift: Summarizes the notion that population changes occur due to random chance.

• Natural Selection: Considered the primary mechanism of evolution.

Natural Selection Simulation

• Run simulations to observe evolutionary changes in different environments.

• Data Collection: Complete a chart tracking percent changes in various color prey within different environments:

  • Grassland, Mountain, Rock Desert Sand

• Adaptation Observations:

  • a. In the grassland,

  • b. In the mountain rock,

  • c. In the desert sand,

Speciation

• Definition: Speciation is the evolutionary process where populations evolve to become distinct species.

• Genetic Changes: Show scenarios that explain speciation over time.

  • Disaster strikes

  • Populations diverge

  • Reunion of populations

Natural Selection and Adaptation

• Environment in New Mexico’s Valley of Fire: Describe the landscape.

• Rock Pocket Mouse:

  • On sand: (blends in/stands out).

  • On volcanic rock: (blends in/stands out).

• Color Change Factors: Discuss what drives fur color change within the mouse population.

• Changes from lighter to darker fur can result from mutations.

• Review:

  • Answer true or false questions regarding mutations and provide explanations.

  • Describe how natural selection manifests in the rock pocket mice.

• Selection Type: Identify whether selection is stabilizing, disruptive, or directional.

Cetaceans and Evolution Evidence

• Close Living Relatives of Cetaceans: Discuss anatomical, fossil, embryonic, and DNA evidence.

• Anatomy:

  • Count the anatomical characteristics shared with mammals and fish.

• Fossil Evidence: Summarize changes over time in fossil cetacean ancestors.

• Embryos & DNA: What do the positions of nostrils and hindlimbs reveal?

• Casein Protein Study: Identify which animal shares traits most closely with whale proteins.

• Evolution of Cetaceans Over Time:

  • Discuss how understanding evolved from the 1700s to modern day via anatomy, fossils, embryological development, and DNA.