Biodiversity Section 1

Objectives

• Describe the diversity of species types on Earth, relating the difference between known numbers and estimated numbers.

• List and describe three levels of biodiversity.

• Explain four ways in which biodiversity is important to ecosystems and humans.

• Analyze the potential value of a single species.

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• Biodiversity (biological diversity)

– the variety of organisms in a given area

– the genetic variation within a population

– the variety of species in a community

– the variety of communities in an ecosystem.

• Certain areas (tropical rainforests) contain an extraordinary variety of species.

• Humans need to understand and preserve biodiversity for our own survival.

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Unknown Diversity

• The number of species known about 1.7 million

– most are insects

• Actual number of species unknown.

– estimate: greater than 10 million

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Unknown Diversity

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Unknown Diversity

• Unknown species exist in all areas

• Species harder to study receive less attention than large, familiar species.

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Levels of Diversity

• Species diversity

– differences between populations of species

– differences between species.

• Ecosystem diversity

– variety of habitats, communities, and ecological processes within and between ecosystems

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Levels of Diversity

• Genetic diversity

– different genes contained within all members of a population.

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Benefits of Biodiversity

Ecosystems

• Biodiversity can affect the stability of ecosystems and the sustainability of populations.

• Healthy ecosystems ensure balanced cycles of energy and nutrients.

• Every species is connected to others in some way, loss breaks food web

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• Keystone species

• critical to the functioning of the ecosystem in which it lives

• affects the survival and abundance of many other species in its community.

• An example: sea otter in kelp beds

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• Genetic variation increases the chances that some members of the population may survive environmental pressures or changes.

• Inbreeding means members of the population may become more likely to inherit genetic diseases

Genetics

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• Drugs (1/4 in US) derived from plants

• Antibiotics derived from chemicals in fungi

• New chemicals and industrial materials being developed from chemicals discovered in all kinds of species.

Medical and Industrial Uses

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Medical Uses

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• ethical reasons

– have a right to exist whether or not they have any other value.

• aesthetic or personal enjoyment

• Ecotourism: tourism that supports the conservation and sustainable development of ecologically unique areas.

Ethics, Aesthetics, and Recreation