Study Notes
Evolution is the change in the heritable characteristics of a species over time, primarily driven by natural selection. Evidence for evolution includes fossils, selective breeding, homologous structures, and patterns of variation.
- Fossil Evidence — Fossils are preserved remains or traces of organisms from the past. Example: Comparing hominin skeletons like Australopithecus with modern humans shows evolutionary changes.
- Selective Breeding — Artificial selection where humans breed species for desired traits. Example: Breeding dogs for specific traits like speed or size.
- Homologous Structures — Anatomical features with similar structures but different functions. Example: The pentadactyl limb in vertebrates like dolphin fins and bat wings.
- Speciation — The process where populations evolve into separate species. Example: Darwin's finches on the Galapagos Islands.
- Patterns of Variation — Continuous variation across geographical ranges indicating gradual divergence. Example: The Red Grouse and Willow Ptarmigan were once considered separate species.
Exam Tips
Key Definitions to Remember
- Evolution
- Fossil Evidence
- Selective Breeding
- Homologous Structures
- Speciation
Common Confusions
- Difference between acquired and heritable characteristics
- Homologous vs. analogous structures
Typical Exam Questions
- What is evolution? Evolution is the change in allele frequency in a population over generations.
- How do fossils provide evidence for evolution? Fossils show changes in species over time, indicating evolutionary processes.
- What is selective breeding? Selective breeding is the human-driven process of breeding for desired traits.
What Examiners Usually Test
- Understanding of natural selection as a mechanism of evolution
- Ability to explain evidence supporting evolution
- Examples of homologous structures and their significance