Download Man-Made factors of Extinction

Natural and Man-Made Extinction Factors Notes
THESE ARE YOUR LAST SET OF NOTES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 
Extinct: no members of a particular species are living.
Most organisms that have ever lived on Earth are now extinct.
Natural factors of Extinction
 have been documented and studied over the course of Earth’s history
o Volcanic eruptions (and their side effects)
o Global warming and global cooling (ice ages)
o Changes in oxygen levels in seawater
o Massive impact from an asteroid or comet
o Competition for Resources: too many organisms fighting over the same food/water/etc.
o Inability to Adapt: cannot change with their changing environment
When species become extinct, the opportunity exists for another species to fill that
ecological hole
(Example) Dinosaurs go extinct, Mammals become dominant
Not all extinctions that have occurred naturally throughout Earth’s history have had a
negative impact. Some of these extinctions have often cleared the way for new kinds of
life to emerge.
Man-Made factors of Extinction
 have caused extinctions in more recent (current) times
o Cutting down trees of the rainforest regions
o Removing natural habitats to build things
o Over-harvesting: planting in the ground until it is no longer fertile
o Pollution: trash, dirty air, dirty water, etc.
Scientists have evidence to support claims that humans have contributed to the
extinction of many species throughout human history, including the woolly mammoth.
Scientists have evidence to support the claims that many plants and animals are
likely to become extinct in the near future as a result of the negative impact of human
activities (tree-cutting, water and air pollution, etc.) on the environment.
Scientists have evidence to support the claims that human effects on the environment
could threaten some biological resources that organisms, including humans, may need for
survival.