1. Evolution
Definition
Evolution is the change in species over time.
Species evolve because:
- organisms vary
- environments select helpful traits
- survivors reproduce
- traits are inherited
2. Natural Selection
The MOST Important Process
Organisms with useful traits survive and reproduce more successfully.
Over generations:
→ helpful traits become common.
The 6-Step Process
- Variation exists
- Selection pressure occurs
- Best adapted survive
- Survivors reproduce
- Traits passed to offspring
- Population changes
3. Adaptations
Definition
An adaptation is a feature that helps survival.
Types:
| Type | Example |
|---|---|
| Structural | Thick fur |
| Behavioural | Migration |
| Physiological | Venom |
Adaptation Examples
4. Evidence for Evolution
Fossils
Show organisms changing over time.
DNA
Similar DNA = closely related species.
Comparative Anatomy
Similar bone structures suggest common ancestors.
Evidence Diagram
5. Darwin’s Theory
Charles Darwin
Proposed evolution by natural selection.
Key idea:
Nature “selects” organisms best suited to survive.
Darwin’s Finches
Different beaks helped birds survive on different foods.
6. Speciation
How New Species Form
- Populations become isolated
- Different environments create different pressures
- Differences build up over time
- New species form
7. Human Influence
Artificial Selection
Humans breed organisms for desired traits.
Example:
- dogs
- crops
Antibiotic Resistance
Bacteria evolve resistance through natural selection.
Antibiotic Resistance
HIGH VALUE EXAM ANSWERS
Explain Natural Selection
Use these words:
- variation
- survival
- reproduction
- inheritance
Model Answer
Organisms in a population show variation. Some traits help survival. Organisms with helpful traits survive and reproduce more. These traits are inherited by offspring, causing the population to change over generations.
Explain Adaptation
Model Answer
An adaptation is a feature that improves an organism’s chance of survival and reproduction in its environment.
Explain Fossil Evidence
Model Answer
Fossils show that organisms from the past were different from modern organisms, providing evidence that species change over time.
MEMORY TRICK
V → S → S → R → I → C
Variation
Selection pressure
Survival
Reproduction
Inheritance
Change
MUST KNOW EXAMPLES
| Topic | Example |
|---|---|
| Natural Selection | Peppered moth |
| Fossils | Archaeopteryx |
| Adaptation | Polar bear |
| Artificial Selection | Dog breeding |
| Resistance | Antibiotic-resistant bacteria |
Victorian Curriculum focus:
- evolution
- natural selection
- variation
- adaptation
- speciation
- evidence for evolution
Related genetics support material appears in your uploaded Year 10 genetics notes.