ocr as biology unit 2 module 3 extinction + conservation

Extinction and Loss of Biodiversity By Iris and C-J

Contents

Extinction

Why it happens

‘good’ extinctions

Loss of biodiversity

Extinction

Extinction is when a species ceases to exist.

Bye Bye!!!

Why extinction happens

Genes can affect extinction

Harmful human activities

Hybridisation

Habitat degradation

‘alien’ organisms creating competition

Connected extinction

Natural phenomena (dinosaurs)

Not all extinctions are bad…

Extinction of bacteris

E.g. smallpox

Loss of Biodiversity

When a species becomes extinct the niche it lives in has biodiversity. Biodiversity is the variation of life within a certain ecosystem.

Harmful human activities

Increase in human population – increased use of land for homes and growing food crops

Deforestation

Global warming

Extinction of species

Damage to natural ecosystem

Why Conserve?

By Iris and C-J

Contents

Why conserve biodiversity / species

Economical + Ecological reasons

Ethical + Aesthetic reasons

Agricultural reasons

Medical reasons

Ways to help conserving

Why conserve biodiversity / species (in general)?

Human activities are causing a loss of biodiversity

Loss of biodiversity is causing a decrease in the gene pool

For survival of humans

Food

Fresh water

Removing our waste

Balance of global ecosystems

Economic + Ecological reasons

Keystone species are important in regulating ecosystems

A keystone species is a species that has a disproportionate effect on its environment relative to its abundance (Wikipedia)

E.g. sea stars, elephants in the African savanna (grassland)

Evolution as our problem-solving tool

Soil becoming infertile

Creating food shortages and elevation of staple crops’ prices

Ethical + Aesthetic reasons

Species having public appeal

Loss of habitat

People enjoy observing wildlife

E.g. chalk down land + heath land

For personal wellbeing

Agricultural reasons

Reserving gene information

E.g. of wheat, rice and maize

Selective breeding causing lost of genes of naturally adapted animals and crops

Research into new crop varieties

Spreading of diseases in crops

Fungal pathogen of wheat plant

Medical reasons

Plants have complex metabolisms

E.g. vinblastine – treating breast cancer, some lung cancer and testicular cancer

E.g. TAXOLTM (paclitaxel) – treating lung, ovarian and breast cancer

Traditional Chinese medicine

Herbalism

E.g. Pei Pa Koa –relief cough, sooth sore throat and remove phlegm

Help conserve species Don't buy imported exotic species for pets (parrots, frogs, lizards, fish, etc.).

Support responsible ecotourism and conservation programs.

Watch where you step – not on rare plants

Drive slowly and attentively in wildlife areas.

Shop smart/shop green

Use less

Recycle!