19,916
edits
Changes
no edit summary
===About Extinction===
*A sudden change in temperature.
*A loss of habitat
*An isolated [[Biological Community|community]] comes in contact with another.
*Pollution
*Hunting
===Examples===
| style="height:20px; width:200px; text-align:center;" |272 million years ago the [[atmosphere]] became [[pollution|polluted]] with [[Hydrogen Sulphide|hydrogen sulphide]] [[gas]], causing all the dimetrodons to [[suffocate]], making them '''extinct'''.
|}
==Key Stage 4==
===Meaning===
[[Extinction]] is when all of the members of a [[species]] have died.
===About Extinction===
[[Extinction]] can be caused by a number of factors:
*A sudden change in temperature.
*A loss of habitat
*A food source disappearing.
*An isolated [[Biological Community|community]] comes in contact with another.
*Pollution
*Hunting
===Mass Extinctions===
Since life began on [[Earth]] there have been 5 great [[Mass Extinction|mass extinctions]]:
Ordovician–Silurian Extinction - 439 million years ago 86% of life on [[Earth]] was made '''extinct''' by the climate rapidly cooling.
Devonian Extinction - 364 million years ago 75% of life on [[Earth]] was made '''extinct''' too many [[nutrient]]s washed into the oceans causing [[eutrophication]] killing sea life.
Permian–Triassic extinction - 251 million years ago 96% of life on [[Earth]] was made '''extinct''' when [[Volcano|volcanic]] eruptions ignited coal deposits poisoning the atmosphere.
Triassic–Jurassic extinction - Between 199 to 214 million years ago many species became '''extinct''' due to a number of events including climate change. This [[extinction]] led to the dominance of [[dinosaur]]s.
Cretaceous–Paleogene extinction - 66 million years ago 76% of life on [[Earth]] was made '''extinct''' due to an [[asteroid]] impact on [[Earth]]. This [[extinction]] led to the end of [[dinosaur]]s and the dominance of [[mammal]]s.