1. Unit 8 – Evolution Learning Activities

2. Evolution Topics Evidence of Evolution Mechanisms of Change
Biogeography
Fossil Record
Molecular Homology
Anatomical Homology
Developmental Homology
Mechanisms of Change
Gene Flow
Genetic Drift
Mutations
Recombination
Natural Selection

3. Definition
Example in Whales
Evidence Validity Rating 1-5 (1 not valid, 5 extremely valid)
Structural Homology (anatomy comparison)
Fossil Record
Molecular Homology (DNA Comparisons)
Biogeography (species distribution)
Developmental Homology
(embryo comparison)

4. Evidence of Evolution
“What is the Evidence of Evolution?” by Stated Clearly
Fill in the chart from the previous slidewith the evidence of evolution
Biogeography, Fossil Record, Molecular Homology (DNA comparison), Structural Homology (anatomy comparison), & Developmental Homology (embryo comparison)
Summary
Explain why you gave the highest rating to an evidence of evolution. Explain why you gave the lowest rating to an evidence of evolution.

5. Structural Anatomy
Vestigial Traits: trait without a use but are present in a species because they had a beneficial function
Give another example.
Homologous Traits: traits with similar characteristics that came from a common ancestor due to different environments
Analogous Traits: traits with similar function that came from two different ancestor due to a similar environment
appendix

6. Fossils Fossils can look at transitional features
Transitional features – traits in fossils that link two organisms in an evolutionary tree
Why are transitional features important in evolution?

7. Biogeography
Species in close proximity originated from the same species but adapted to their new environment.

8. Biogeography Example
Based on their traits, describe the environment that two of these organisms currently live. Describe the specific traits that helped them adapt.

9. Mechanisms of Change

10. Definition
Example in Beetles
Genetic Variation (increased or decreased)
Natural Selection
Genetic Drift
Gene Flow
Mutation
Genetic Recombination

11. Mechanisms of Change
Natural selection Imagine that green beetles are easier for birds to spot (and hence, eat). Brown beetles are a little more likely to survive to produce offspring. They pass their genes for brown coloration on to their offspring. So in the next generation, brown beetles are more common than in the previous generation.

12. Mechanisms of Change
Genetic drift Imagine that in one generation, two brown beetles happened to have four offspring survive to reproduce. Several green beetles were killed when someone stepped on them and had no offspring. The next generation would have a few more brown beetles than the previous generation — but just by chance. These chance changes from generation to generation are known as genetic drift.

13. Mechanisms of Change Gene Flow (Migration)
Some individuals from a population of brown beetles might have joined a population of green beetles. That would make genes for brown coloration more frequent in the green beetle population than they were before the brown beetles migrated into it.

14. Mechanisms of Change
A mutation could cause parents with genes for bright green coloration to have offspring with a gene for brown coloration. That would make genes for brown coloration more frequent in the population than they were before the mutation.

15. Mechanisms of Change Genetic Recombination
sexual reproduction can introduce new gene combinations every generation into a population and is an important source of genetic variation.
Gg x Gg g G G GG Gg g Gg gg

16. Natural Selection
To prevent extinction, there needs to be a cycle of survival and reproduction of a species
Involves adapting to a change in the environment
Introduction of a predator
Limited resources
Climate changes
Explain why genetic variation is important in survival and reproduction of a species?