A4.2 Extinction (SL)

Vocabulary flashcards covering the major terms and concepts from the lecture on biodiversity, extinction, and conservation.

Biodiversity

The variety of life at all levels of biological organisation, including genes, species and ecosystems.

Genetic Diversity

Variation of genes and traits within a single species’ population.

Species Diversity

The variety of different species present within an ecosystem.

Ecosystem Diversity

The range of different habitat types found in a given area of land or water.

Species Richness

The total number of different species in a specified area.

Species Evenness

The relative abundance of each species present in an area.

Simpson’s Reciprocal Index (D)

Mathematical measure of biodiversity; higher D indicates greater diversity [D = N(N – 1)/Σn(n – 1)].

Lumpers

Taxonomists who classify organisms by grouping similar forms together, yielding lower species counts.

Splitters

Taxonomists who emphasise differences and separate organisms into more species, yielding higher species counts.

Speciation

Evolutionary process by which new species arise, often after reproductive isolation and genetic divergence.

Reproductive Isolation

A barrier preventing gene flow between populations, leading to potential speciation.

Diversification

Increase in genetic and species variety through mutation, recombination and speciation.

Biodiversity Crisis

Current rapid decline in global biodiversity caused mainly by human activities.

Anthropogenic Mass Extinction

A human-driven, large-scale loss of species comparable to past geological mass extinctions.

Overexploitation

Excessive hunting, fishing or harvesting that depletes natural populations.

Climate Change (as a threat)

Human-induced alteration of global climate patterns that stresses ecosystems and species.

Urbanisation

Expansion of cities that leads to habitat loss and fragmentation.

Pollution

Contamination of air, water or soil (e.g., microplastics, fertilisers) harming biodiversity.

Invasive Species

Non-native organisms that spread, outcompete natives and disrupt ecosystems.

Deforestation

Large-scale removal of forest cover, reducing habitat and biodiversity.

O! CUPID

Mnemonic for human pressures causing biodiversity loss: Overexploitation, Climate change, Urbanisation, Pollution, Invasive species, Deforestation.

Ecosystem Loss

Destruction or severe degradation of natural communities and their interactions.

Dipterocarp Forest

Southeast Asian mixed forest type threatened by logging and conversion to palm-oil plantations.

Great Barrier Reef Bleaching

Loss of symbiotic algae from coral polyps due to rising sea temperatures, leading to reef decline.

Extinction

The complete disappearance of a species or higher taxon.

Mass Extinction Event

A geologically short interval during which an exceptionally high number of species die out.

North Island Giant Moa

Flightless New Zealand bird hunted to extinction after Polynesian colonisation (last sighting ~1300s).

Caribbean Monk Seal

Docile marine mammal hunted for oil, declared extinct after last sighting in 1952.

Tasmanian Tiger (Thylacine)

Carnivorous marsupial hunted after European settlement; last confirmed sighting 1936.

Conservation

Protection and preservation of species and their habitats, implemented in situ or ex situ.

In Situ Conservation

Safeguarding species within their natural habitats (e.g., national parks, nature reserves).

Ex Situ Conservation

Protecting species outside their natural habitats (e.g., zoos, seed banks).

Rewilding

Restoring an area to a self-sustaining natural state by re-establishing native species and processes.

Reclamation

Repurposing degraded land (e.g., quarries) to re-establish pre-existing ecosystems.

Captive Breeding Programme

Controlled breeding of endangered animals in captivity to boost population numbers.

Botanical Garden

Institution dedicated to cultivating and displaying a wide variety of plant species for conservation and education.

Seed Bank

Secure facility where seeds are stored at low temperature and humidity for long-term conservation.

EDGE of Existence Programme

Initiative that prioritises species for conservation based on being Evolutionarily Distinct and Globally Endangered.

EDGE Species

Species with few close relatives (high distinctiveness) and high threat level (IUCN globally endangered).

IUCN Red List Categories

Standardised scale of extinction risk: EX, EW, CR, EN, VU, NT, LC (from extinct to least concern).