Preserving Biodiversity

Question 1

Extinctions

Answer 1

• Biodiversity over time is a balance between speciation and extinction
• Mass extinctions are dramatic losses of species

Question 2

Modes of Speciation

Answer 2

When a population is split, two
groups can begin to diverge into
new species (Allopatry)

• Dispersal= portion of population
  moves
• Vicariance= natural barrier created to
  split population

New species can evolve within
and amongst existing populations
(Sympatry)

Question 3

Recent Extinctions

Answer 3

Birds hunted to extinction by explorers for food (and down feathers) (ex : dodo bird)

Mammals hunted to extinction by settlers to reduce competition with livestock (ex : grizzly bear)

Question 4

Extinction Rates

Answer 4

Most extinctions are occurring unkowingly to people
- The total number of aspecies is unknown and many are still being described
- Undescribed species may be disappearing without humans knowing about it

Question 5

Background Extinction Rate

Answer 5

Losses seen in modern times are outpacing (greater than)
background extinction rates (extinctions that normally occur)

Question 6

Preserving Biodiversity - National parks and preserves

Answer 6

Landholdings left in unchanged presence as refuges for biodiversity
- Can include biodiversity hotspots (areas w/ high numbers of endemic species)

Question 7

Preserving Biodiversity - Habitat restoration

Answer 7

Returning ecosystems to previous conditions, including wildlife reintroduction

Question 8

Preserving Biodiversity - Legislation and agreements

Answer 8

Regional laws to protect ecosystems/species and can be enforceable
- e.g., Environmental Protection Act, Endangered Species Act

• International agreements address concerns that extend beyond political boundaries e.g., Kyoto Protocol, Paris Accords