SAT Subject Test in Biology

The SAT Subject Test in Biology assesses students' understanding of biological concepts and principles.

Cell Structure and FunctionGenetics and HeredityPhotosynthesis and Cellular Respiration
Evolution and Natural SelectionEcology and EcosystemsHuman Body Systems
Biotechnology in MedicineConservation and Environmental ProtectionGenetic Testing and Personalized Medicine
Time Management and PacingProcess of Elimination
Cell Structure and F...Genetics and Heredit...Photosynthesis and C...Evolution and Natura...Ecology and Ecosyste...Human Body SystemsBiotechnology in Med...Conservation and Env...Genetic Testing and ...Time Management and ...Process of Eliminati...
Advanced Topics

Evolution and Natural Selection

How Species Change Over Time

Evolution is the process by which species change over generations through genetic variation and natural selection.

Darwin's Theory

Charles Darwin proposed that organisms with traits best suited to their environment are more likely to survive and reproduce. Over time, these traits become more common.

Mechanisms of Evolution

  • Mutation: Random changes in DNA introduce new traits.
  • Gene Flow: Movement of genes between populations.
  • Genetic Drift: Random changes in gene frequencies, especially in small populations.

Evidence for Evolution

Fossil records, comparative anatomy, and molecular biology all support the theory of evolution.

Why It Matters

Understanding evolution helps explain biodiversity, antibiotic resistance, and the development of new species.

Examples

  • Peppered moths changed color during the Industrial Revolution due to pollution.

  • Bacteria evolve resistance to antibiotics through natural selection.

In a Nutshell

Evolution explains how species adapt and change over time due to natural selection and genetic variation.

Key Terms

Natural Selection
The process by which organisms better adapted to their environment survive and reproduce.
Mutation
A change in the DNA sequence.
Speciation
The formation of new and distinct species in the course of evolution.
Next
Ecology and Ecosystems