Topic 3 definitions

Habitat diversity

Range of habitats in an ecosystem.

Species diversity

no species present and relevant abundance.

genetic diversity

range of genetic material in a gene pool.

what falls under the umbrella of biodiversity

habitat → species → genetic

Higher species richness

communities with higher species richness with 1 dominant species have low diversity. Can’t support a wide variety of organisms.

Biodiversity hotspots

• in need of emergency conservation

• rich in endemic plants and animals

• tropical rainforests

• - constant threat

• - timber demands

• - carbon stores

• - found in LEDC’s or NIC’s.

evolution

change in genetic character of populations over generations (natural selection, reproductive success)

evolution:

1. variation

2. competition

3. adaptations

4. selection

speciation

new species when populations of species are separated.

isolation

• geographical (movement of plates, creates mountains, oceans etc)

• mechanical

• behavioural

• genetic

types of extinction

• local

• ecological

• biological

main factors of extinction

• hunting

• habitat destruction

• introduction of exotic species

prone to extinction

• small populations

• quality of habitat (if its bad)

• specialists - if they only eat one food it then may become tricky to find that one food, leads to them dying.

• large mammals (meat to eat)

• poor competitors

• charisma (like tigers have lots of charisma so get funding, but walruses don’t)

factors that go towards conservation:

• aesthetic

• ecological

• economic

• ethical

• social justifications