Chapter 28 - Conservation of Biodiversity Flashcards
When is a species extinct?
When there are no living representations left.
After how long is a species considered extinct by conservation organizations?
After it has not been seen or recorded fro 50 years.
What is the background extinction rate?
Expect species to disappear at some low rate.
What is the number for the background extinction rate
(approx. 10% every million years)
End of Devonian period date?
359 mya
Most severe extinction?
Permian
What percent of species disappeared with the Permian extinction?
More than 85% of species
What percent of species disappeared at the end of the Cretaceous period?
Half of the species, most dinosaurs.
What will cause the 6th mass extinction?
Human degradation of the environment.
6th mass extinction rate?
1000 species/ per year/ per million of species.
Cretaceous extinction cause?
Asteroid Impact
Time of end-Ordovician extinction?
450 mya
End- Permian time?
250 mya
Late-Devonian
375 mya
End-Triassic
200 mya
End-cretaceous
65.5 mya (double check)
What is the Anthropecene Extinction Event?
6th mass extinction, potentially largest of all
What did the asteroid 65.5 mya ago cause?
- dust clouds blocked sunlight for photosynthesis
- chain reactions, began with microscopic marine organisms and finished with dinosaurs
Why did the Australian gastric brooding frog go extinct?
Wiped out due to degredation of stream habitats, pollution and possible disease
Examples of vulnerable species?
-endemic to islands (especially flightless birds)
Characteristics of island species?
- small poulations
- unaccostomed to terrestrial predators
- expanding human popilations
How did the Stephens Island Wren go extinct?
The lightkeepers cat
Where did the Dodo live?
Maruritius in the Indian Ocean
Last account of the Dodo?
1662
