ESS Topic 3 - Key Terms

Biodiversity

The variety of all life on Earth, including genetic, species, and habitat diversity.

Genetic diversity

The range of genetic material present in a population of a species.

Species diversity

The number of different species and their relative abundance in a community.

Habitat diversity

The range of different habitats in an ecosystem, biome, or the whole planet.

Evolution

The cumulative change in the heritable characteristics of a population over successive generations.

Natural selection

The process by which individuals with advantageous traits survive and reproduce more successfully.

Speciation

The formation of new species when populations of a species become isolated and diverge genetically.

Direct threats

Human actions that immediately affect species (e.g., overharvesting, poaching, illegal trade).

Indirect threats

Human activities that indirectly affect biodiversity (e.g., habitat destruction, pollution, climate change, invasive species).

Invasive species

Non-native species that spread rapidly and outcompete or harm native species.

Keystone species

A species with a disproportionately large impact on its ecosystem relative to its abundance.

Umbrella species

A species whose protection indirectly protects many others in its ecosystem.

Flagship species

A charismatic species chosen to represent a conservation campaign and raise awareness.

Limiting factor

A factor (biotic or abiotic) that restricts the growth or distribution of a population.

Carrying capacity

The maximum population size an environment can sustainably support.

Conservation

The sustainable management of natural resources to maintain biodiversity.

In-situ conservation

Conserving species in their natural habitat (e.g., protected areas, national parks).

Ex-situ conservation

Conserving species outside their natural habitat (e.g., zoos, seed banks, captive breeding).

Protected area (National Park)

A designated region where human activity is limited to protect biodiversity.

UNESCO Biosphere Reserve

A protected area model with core, buffer, and transition zones balancing conservation and sustainable use.

Wildlife corridor

A natural strip of habitat connecting separated populations to reduce fragmentation.

IUCN Red List

A global inventory that categorizes species according to their risk of extinction.

CITES

Convention on International Trade in Endangered Species, an international agreement regulating trade in endangered species.

CBD

Convention on Biological Diversity, a global treaty aimed at conserving biodiversity and promoting sustainable use.

NGO

Non-Governmental Organization, e.g., WWF, Greenpeace, that raise awareness and implement conservation projects.

IGO

Intergovernmental Organization, e.g., UNEP, FAO, UNESCO, that influence policy and conservation.

Simpson's Diversity Index (D)

A measure of biodiversity that accounts for species richness and relative abundance.