1. A BRIEF REVIEW OF SUBTOPICS
UNIT 4 – Evolution
A BRIEF REVIEW OF SUBTOPICS

2. Adaptation & Variation
Extinction
Adaptations:
Structural
Behavioural
Physiological
Variations
How do variations develop?
How do variations become adaptations?

3. Adaptation & Variation (con’t)
Mutations
Selective advantage
Eg. Antibiotic resistance in staph. bacteria

4. Darwin & Natural Selection
General info about Darwin
General info about voyage of Beagle, research and observations in Galapagos
Eg: Turtles & Finches
Origin of Species
Controversy surrounding Darwin

5. Darwin & Natural Selection (con’t)
Process of change in populations over many generations
Individuals with certain traits survive local environmental conditions
Pass on favourable alleles to offspring
Environment exerts ‘selective pressure’
Assumptions of Natural Selection
Variation
Competition
Fitness
Adaptation

6. Darwin & Natural Selection (con’t)
Concepts:
Natural Selection
Fitness
Selective pressure
“Descent with Modification”
Artificial selection

7. Mechanisms of Evolution
Factors that Change Allele Frequencies:
Mutation
Gene Flow (Migration)
Non-Random Mating
Genetic Drift
Natural Selection

8. Mechanisms of Evolution (con’t)
“The Bottleneck Effect”
“The Founder Effect”

9. Types of Natural Selection
RECALL:
Result of the environment selecting for individuals with certain traits that make them better suited to survive and reproduce
Over many generations, frequency of alleles of many different genes may change, resulting in significant changes

10. Types of Natural Selection (con’t)
Stabilizing Selection
Directional Selection
Disruptive Selection
Sexual Selection

11. Types of Natural Selection (con’t)
Long Term Evolution:
Gradualism
Punctuated Equilibrium

12. Evidence of Evolution Topics Discussed: Fossil record
Radiometric Dating
Transitional forms
Biogeography

13. Evidence of Evolution (con’t)
Topics Discussed:
Embryonic development
Homologous structures
Vestigial structures
Atavisms
Micro-evolution happening today

14. Evolution of Humans Early primates
Brain development (cranial capacities)
Transition to 2 bipedal and life out of trees and onto plains
Eg: Ardi

15. THE END …
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