5.2 Extinction and Protecting Species
Evolution doesn't increase or decrease biodiversity
Extinction decreases biodivers
click to edit
Background extinvtio rate typically amounts to a loss of about 1 species per year for 1m species leaving on earth
99% of all species that have existed are extinct
Specitayyion increases biodiversity
If you will take 5 million to 10 million years for natural speciation to replace the species that have become extinct during this century
Speciation rate faster than extinction rate, so biodiversity increases over time
Some species are more vulnerable to extinction
Dot't breed frequently
Specialist
generalists on the other hand are more likely to adapt to human dominated landscapes
High Trophic levels
Live in small range
Commercially valuable
Treaties and laws to protect animals
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora)
Convention on Biological Diversity
The US Endangered Species Act
Protecting Species Ex
Seebanks and botanical gardens
Wildlife Farms
Zoes and aquariums
There has been 5 mass extinctions throughout history
Causes of extinctions
Extinctionrates have increased as the human population has grown and spread over most of the globe
Global warming or cooling
Change in sea levels and ocean water acidity
Volcanic eruptions
Large asteroids
Competitions from newly migrated species