Test 3

Biological Extinction
global extinction, gone from the planet
Almost extinct
The genetic diversity would be so low that when the environment changes the species wouldn’t be able to stand it.
Ecological Extinction
The number is so few that the species isn’t fulfilling their niche
Population is noticeably declining, but not yet endangered. Still able to be fixed.
Local extinction
Species not found in area that it used to be found in.
Rate of Extinction + Human influence
0.1%-1.0% of all species goes extinct per year.
Don’t know what it would be without human influence, but probably 10x slower.
Nature will “replace” the organism that left the niche open, but we don’t know if nature can speed it up to accommodate human influence.
Characteristics that make more species vulnerable to premature extinction
1) K-selected species, having a low “r”
2) Being a specialist
3) Having a narrow distribution (ie: horseshoe crabs being found in only 2 locations on Earth)
4) Being an upper level consumer
5) Having a fixed migration rate (ie: Ducks going up/down coast and not having wetlands=bad)
6) Having a commercial value ($ for humans)
Passenger Pigeon Example
Humans drove to extinction
They liked to nest on top of each other=specialist=easy to kill (shoot)
Millions to zero
Habitat Destruction
Invasive Species
Population Size
Climate Change
Habitat Destruction
Doesn’t always have to be destruction, can be habitat fragmentation.
Invasive Species
1 nonnative species replaces many native species
Population Size
Human population size–>Everything worse with more people on the planet
Pollution (+example)
Ex. Runoff with pesticide
DDT used on crops in the 60s but banned in the 70s. Made thinner shells for bird eggs, causing the population of birds to drastically drop due to low birth rates.
Taking any organism from the environment.
We only make laws when we have to because of future profits.
Climate Change
Environments change, but human could’ve made it more difficult for the environment to catch up.
Endangered Species Act
Conventions on International Trade in Endangered Species (CITES)
Identifying what is endangered
US Fish and Wildlife
Terrestrial and fresh water species
National Marine Fisheries Service
Saltwater species; commercial
Most laws would get passed if they would be strictly enforced
We only improve/recover the things that people will pay money for/to hunt. Because that’s where the money comes for.