IB ESS - Topic 3

Species Diversity

The number and relative abundance of species in a biological community.

Genetic Diversity

a measure of the genetic variation among individuals in a population

Habitat Diversity

the range of different habitats in an ecosystem or biome

biodiversity hotspots

a region with a high level of biodiversity that is under threat from human activities

Theory of Evolution

states that organisms change and develop over time to adapt an increase rate of survival

The Origin of Species

1859: Charles Darwin's book explained how various species evolve over time and only those with advantages can survive and reproduce

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

"Survival of the fittest"

Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection

Speciation

the formation of new and distinct species in the course of evolution. Can be sped up by humans through artificial selection and by genetic engineering.

artificial selection

Breeding organisms with specific traits in order to produce offspring with identical traits.

Continental Drift

The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations

Plate tectonics

The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.

background extinction rate

The average rate at which species become extinct over the long term; hypothesized to be 10-100 species per year

Mass extinction

event during which many species become extinct during a relatively short period of time (over 75% of all species disappear); there have been 5 mass extinctions on Earth

6th mass extinction

We are now considered to be in the 6th mass extinction, an inter-glacial period. The sixth mass extinction is likely being caused by human-induced events which destroy species habitats. Known as the Holocene extinction event.

weedy species

the species (generally plant or animal) which are able to survive the environments we create e.g. urban rats, domesticated animals

Current Extinction Rate

1,000-10,000 times the background extinction rate; about 30,000 species per year

Extinction Hotspots

regions with high levels of biodiversity loss and a large number of threatened or endangered species

Natural Hazards

natural events in the physical environment that are destructive, such as volcanoes and hurricanes

loss of habitat

the decline in areas of land where animals and plants would normally exist

fragmentation of habitat

Process whereby a large area is divided up into a patchwork of fragments, separated from each other by roads, towns, factories, fences, power lines, pipelines, or fields

pollution

the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects.

overexploitation

Practice of harvesting or hunting to such a degree that remaining individuals may not be able to replenish the population

introduction of non-native species

when a species which is not naturally occurring in an ecosystem is introduced and may out-compete the native species - this may lead to a loss of biodiversity e.g. rabbits, cane toads, red foxes, camels in Australia

spread of disease

large outbreaks of disease may devastate wild and/or domestic populations of animals, reducing biodiversity

Modern agricultural practices

These practices include monocultures, genetic engineering and pesticides. Fewer and fewer species and varieties of species are grown commercially, and more pest species are removed causing a threat to biodiversity

minimum viable population

The smallest population size at which a species is able to sustain its numbers and survive.

IUCN

International Union for the Conservation of Nature; a coalition of the world's leading conservation groups

IUCN Red List

the conservation status of species based on: population size, degree of specialisation, distribution, reproductive potential, geographic distribution and fragmentation, habitat quality, trophic level and therefore, the probability of extinction

Extinct (EX)

IUCN Red List Status - no reasonable doubt that the last of a species has died

Extinct in the Wild (EW)

IUCN Red List Status - a species is known only to survive in cultivation, captivity or outside of its past range

Critically Endangered (CR)

IUCN Red List Status - at extreme risk of extinction in the wild

Endangered (EN)

IUCN Red List Status - facing a very high risk of extinction in the wild

Vulnerable (VU)

IUCN Red List Status - facing a high risk of extinction in the wild

Near Threatened (NT)

IUCN Red List Status - likely to qualify as vulnerable or endangered in the near future (but does not yet)

Least Concern (LC)

IUCN Red List Status - widespread and abundant

Data Deficient (DD)

IUCN Red List Status - when there is insufficient data to determine a species' status

Not Evaluated (NE)

IUCN Red List Status - when a species has not been evaluated against the criteria

Endangered Species Act

(1973) identifies threatened and endangered species in the U.S., and puts their protection ahead of economic considerations

CITES

Convention on International Trade in Endangered Species; a 1973 treaty formed to control the international trade of threatened plants and animals

non-governmental organization (NGO)

Private organizations that pursue various activities including, but not limited to conserving and restoring ecosystems and biodiversity.

WWF

Worldwide Fund for Nature

UNEP

United Nations Environment Programme

UN

United Nations

Greenpeace

an international organization that works for environmental conservation and the preservation of endangered species

Conservation Biology

The integrated study of ecology, evolutionary biology, physiology, molecular biology, and genetics to sustain biological diversity at all levels.

Preservation Biology

field of biology that attempts to exclude human activity in areas where humans have not yet encroached.

Keystone Species

A species that influences the survival of many other species in an ecosystem

Protected areas

geographic spaces on land or at sea that are recognized, dedicated, and managed to achieve long-term conservation of nature

IGO

Intergovernmental Organization

GO

Government Organization

umbrella species

species whose being protected under the Endangered Species Act leads to the preservation of its habitat and all of the other organisms in its community

Ecotones

a boundary between two types of ecological communities