20,345
edits
Changes
no edit summary
===Meaning===
A '''mass extinction''' is when a large number of [[species]] in a [[community]] become [[extinct]] at the same time.
==Key Stage 4==
===Meaning===
A '''mass extinction''' is when a large number of [[species]] in a [[community]] become [[extinct]] at the same time.
===About 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 dinosaurs.
*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 dinosaurs and the dominance of [[mammal]]s.
* ... Some scientists believe we are in the middle of another [[Mass Extinction|mass extinction]] caused by [[human]]s because around 200 [[species]] are going '''extinct''' every day.
==Extra Information==
{{#ev:youtube|https://www.youtube.com/watch?v=RAdNCIIYXvo}}