Evolution

Introduction to Evolution

Evolution is the process by which species change over time, giving rise to new species. It is driven by variation, natural selection, and adaptation.

Evidence for Evolution

• Fossil Records: Show progressive changes in organisms over time.
• Comparative Anatomy: Homologous structures indicate common ancestry.
• Embryology: Similar embryonic stages suggest evolutionary relationships.
• Molecular Biology: DNA and protein similarities indicate relatedness.

Mechanisms of Evolution

• Natural Selection: Individuals with favorable traits survive and reproduce.
• Mutation: Changes in DNA can introduce new traits.
• Gene Flow: Exchange of genes between populations.
• Genetic Drift: Random changes in allele frequencies in small populations.

Speciation

Speciation is the formation of new species, usually due to reproductive isolation, adaptation, and selection pressures over time.

Practice Questions

• Define evolution and explain its importance. (4 marks)
• List four types of evidence for evolution. (4 marks)
• Describe three mechanisms of evolution. (5 marks)
• Explain how speciation occurs. (4 marks)
• Draw and label a simple diagram showing evolutionary progression. (3 marks)