3.1 Biodiversity & Evolution

Guiding questions

• How can diversity be explained and quantified, and why is this important?

• How does the unsustainable use of natural resources impact biodiversity?

SL and HL knowledge statements

3.1.1 Biodiversity is the total diversity of living systems and it exists at several levels.

3.1.2 The components of diversity contribute to the resilience of ecological systems.

3.1.3 Biodiversity arises from evolutionary processes.

3.1.4 Natural selection is the mechanism driving evolutionary change.

3.1.5 Evolution by natural selection involves variation, overproduction, competition for limited  resources, and differences in adaptation that affect rates of survival and reproduction.

3.1.6 Speciation is the generation of new species through evolution.

3.1.7 Species diversity in communities is a product of richness and evenness.

3.1.8 Simpson’s reciprocal index is used to provide a quantitative measure of species diversity,  allowing different ecosystems to be compared and for change in a specific ecosystem over time to  be monitored.

3.1.9 Knowledge of global and regional biodiversity is needed for the development of effective management strategies to conserve biodiversity.