Geol 2000: Lessons in Extinction
No members of a species remain alive
Restricted to a certain area
Local extinction, gone from a particular area
Individuals remain, but only in captivity
extinct in the wild
Still persists, but is so rare that its ecological role is negligible
What species exhibit key ecological functions that are not always proportionate to their abundance?
How many known species of plants and animals are there?
What is the estimated total of plants & animals on Earth?
How many species have gone extinct for every species that currently exists?
When were the 5 mass extinctions?
Permian, Devonian, Ordovician, Triassic, Cretaceous
Name the top 2 causes of extinction
loss of suitable habitat & competition, predation & disease associated w/alien invaders
What caused the extinction of the ivory-billed woodpecker?
habitat loss (deforestation)
What is causing the demise of understory plants of the southeast?
competition w/alien plants (kudzu, honeysuckle)
What are the primary causes of the extinction of native Hawaiian birds?
habitat loss, avian diseases, & introduced predators
What caused the extinction of the nenes?
predation by alien animals (mongooses, dogs, cats)
What caused the demise of the American Chestnut?
fungus blight (disease)
What is causing the demise of the Nashville crayfish?
What caused the extinction of the Carolina parakeet?
killed in large numbers b/c they were thought to be an agricultural pest
What caused the demise of the Stellar's sea cow?
What is causing the decline in the West Indian Manatee population?
What caused the decline in the black-footed ferret?
loss of food base (poisoned prairie dogs)
What caused the extinction of the passenger pigeon?
overharvest, loss of habitat, limits on social biology
What are 5 possible causes for the decline in amphibians?
loss of habitat, pollution, disease, UV radiation, acid rain
What is the leading killer of amphibians?
What is the extinction rate in rainforests alone?
What is the rainforest destruction rate?
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