Endangerment and Extinction - Human Impact 1

Reasons for endangerment and extinction, and how it can be helped

What effects does extinction have?

a loss of species and a decrease in biodiversity

How can natural selection be a reason for extinction

during evolution process various species are replaced by others

What are the different reasons for species endangerment as result of human impact

1. Destroying habitats - deforestation, draining wetlands, removing hedges

2. Pollution - PCBs, oil, pesticides

3. Introducing alien species to ecosystem - may out-compete for food and space, may have no predators to control pop. , may carry disease

4. monoculture - growing genetically identical individuals in a given area in large quantities

5. building - roads, housing, factories

6. unsustainable harvesting - overhunting, overfishing

How can endangerment and extinction be prevented?

conservation

What is conservation

creation, management, and protection of habitats

ideally maintains biosphere (worldwide sum of ecosystems) and enhances biodiversity

conservation of existing gene pools in wild and captivity is vital for maintaining biodiversity in the future

How can conservation be achieved

1. Habitat protection - nature reserves and sites of special scientific interest like coral reefs

2. international cooperation between governments - restricting trades in animal goods like ivory, or to ensure that international trade in plants/animals doesn’t affect survival

3. restriction of activities that would threaten an endangered species - whaling

4. introducing legislation - prevent overfishing, poaching, collection of birds eggs, picking of wild flowers

5. breeding programmes

6. sperm banks and seed stores

7. pollution control

8. reintroducing species

Why is conserving gene pools important

when species conserved, gene pool is also

maintain genetic biodiversity, critical for changing environments due to natural selection

may have alleles useful for humans - plants with medicinal properties, disease resistance

captive breeding programmes have moral obligation to maintain genetic biodiversity of captive animal stocks