Environmental Systems and Societies · Topic 3: Biodiversity and conservation
ES3.1 — Biodiversity and evolution
Environmental Systems and Societies · SL / HL · syllabus-mapped notes
Biodiversity and its three levels
Biodiversity as the total diversity of living systems at habitat, species and genetic levels, and how each contributes to resilience.
Evolution, natural selection and speciation
Evolution as cumulative heritable change, the mechanism of natural selection, and how isolation generates new species.
Quantifying species diversity
Richness and evenness, and Simpson's reciprocal index for comparing ecosystems and monitoring change over time.
Knowing biodiversity for management
Why global and regional knowledge is needed for conservation, and how it is gathered from citizen science to parabiologists.
HL: Genetic diversity, isolation and human-driven change
Mutation and sexual reproduction, reproductive isolation and hotspots, and how human activity reshapes selection.
HL: Geological time and the Anthropocene
Deep time and fossils, epochs and mass extinctions, and the debated case for a human-defined geological epoch.