6th Mass extinction

What caused the first 5 extinctions

asteroid, climate chagne due to intense volcanic activity

What were oricional extinction reates

1 out of every 1 million species

What are todays extinction rates

100 to 10,000 times higher than natural rates

What are causes of extinction today

habitat loss

Over exploitation

cheimcal polutatns 

invasive species 

Climate Change

What are natural habitats converted to

agriculture

roads

cities

mines

reservoirs

Can many organisms live in new habitats

no, they have very specific living environments

Why do the organisms that can evolve to live in new places not survive

because the rate of habitat loss is much faster than the rate of evolution

Where is habitat loss happening rappidly 

in the tropics 

How much forest do rain forests loose each day

18 soccer feild sized forests per minute

Why does the midwest have some of the highest rates of habitat loss on earth

we lost 99.9% of tall grass praries

Whayt happens once habitat loss has reached a high level

The remaining blocks of habitat are small and isolated

What does over exploitation interfere with 

poverty and greed and cultural beleifs 

What % of parot species are endangered due to the pet trade

1/3

Why do people in poverty collect and sell parrots

becuase they can feed their familis for a year by selling 2 rare parrots

What are direct impacts of over exploitation

over fishing: 1-3 billion people get their animal proteins from the ocean

Where do cheimcal pollutants come from 

industries, agriculture, land owners 

What are direct mortallity events from chemical pollutants

decrease in reproductive rates

increase in diseases- especially cancer

these can efect hormones

what are indirect mortality rates from chemical pollutants

bird+ bat species are declining becuase insect species are declining becase of chemical pollutatnts

What is an invasive species

a species brought to an area by humans that explodes in population and harms native species

Wht are species moved on purpose

as pets, to hunt, for gardens 

What is an example of how a species was moved on accident

a zebra mussel carried by a ship

Why are invasive species harmful to

they act as predotors

they spread disease

the compete with native

Whta are examples of invasive species acting as predators

house cats casing 33 extinctions

ant released in hawaii causing over 100 extinctions in insects

What are examples of invasive species causing diseases

emerald ash borer killing ash trees

white nose fungus killing bats in hibernation 

What is an example of invasive species competing with native species

Autumn olive shrub over shading and invading praries

Why do invasive species have an advantage over native species

Invasive species dont have predators in their new habitats like insects or diseases so the enrgy they used to spend on fighting these predators can be used to grow rapidly