1. II. Evidence for Evolution:

2. Types of Evolution Micro evolution: 1. evolution on the smallest scale
2. generation to generation change in frequencies of alleles

3. B. Macro Evolution More dramatic biological changes
Evidence found in fossil records
Includes:
Origin of different species
Extinction of species
Evolution of major new features of living things

4. Fossil Records: Left the most evidence
Preserved remains or markings left by organisms
Provide evidence of Earth’s changing life
Can link past & present

5. Geographical Distribution
Differences and similarities between organisms in different parts of the world
Serves as clue as to how species changed
Organisms are more similar to nearby populations with different environments than populations that live far away with similar environments
Darwin noted that blind cave-dwelling animals are more like the animals living near the cave – despite the great difference in cave and surface environments – than they are to animals living in distant caves, even though there is great similarity in the caves’ environments.

6. Similarities in Structures
1. homologous structures: structures that are embryologically similar, but have different functions
ex: forelimbs of mammals
consist of same skeletal
parts but function differ

7. Vestigial Structures:
a. Features that apparently serve no function in an organism
b. are allegedly holdovers from an evolutionary past
ex: pelvic bone of whales
Python Pelvis & Leg

8. 3. Analogous structures – have same FUNCTION but different STRUCTURE
NOT evidence for evolution (Convergent evolution)
Ex: Bird wing and
Butterfly wing

9. Similarities in Development (Embryological)
1. embryos of some organisms have similar
stages of development
* Indicates common ancestor

10. Molecular Biology DNA/amino acid sequences
Greater the differences  less likely shared ancestor

11. F. How does evolution occur?
Natural Selection
Genetic Drift - a change in the gene pool of a population due to chance

12. Populations that are NOT evolving
Hardy-Weinberg Equilibrium
Population that does not undergo change in gene pool
Are not presently evolving
Frequency of gene pool is constant
Rarely occurs for long period of time in nature
Provides “no change” baseline for comparison