Ch58 Flashcards
(9 cards)
1
Q
mass extinction
A
majority of recent extinctions have occurred since 1900.
It is estimated that 20% of present day species may be extinct by the middle of this century
2
Q
causes of extinction
A
- Evolved in the absence of predators.
- Humans introduced competitors, diseases.
- Island populations are usually small, which increases their
risk for extinction.
3
Q
Hotspots
A
areas where species have high endemism and are
disappearing at a rapid rate
4
Q
Endemic species
A
species found naturally in only one
geographic area and no place else.
5
Q
Ecological Economics
A
he study of how the societal
benefits provided by species and ecosystems can be appropriately valued
6
Q
Habitat loss
A
- Pollution
- Catastrophic disturbances.
- Disruption of ecosystem.
- Introduced species
- Loss of keystone species
- Climate change
7
Q
Fragmentation
A
Disastrous consequences of dividing habitat up into small areas
* Smaller populations go extinct more easily
* Environment on edge of habitat is different
8
Q
- Disruption of ecosystem interactions.
A
- Introduced species
- Loss of keystone species
9
Q
Extinction Cascade
A
Effects on one species can have ramifications throughout an ecosystem
