Difference between revisions of "Extinction"
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===Mass Extinctions=== | ===Mass Extinctions=== | ||
| + | When a [[community]] of many different [[species]] become '''extinct''' it is known as a [[Mass Exctinction|mass extinction]]. | ||
Since life began on [[Earth]] there have been 5 great [[Mass Extinction|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. | *Ordovician–Silurian Extinction - 439 million years ago 86% of life on [[Earth]] was made '''extinct''' by the climate rapidly cooling. | ||
Revision as of 09:04, 20 April 2019
Contents
Key Stage 3
Meaning
Extinction is when all the members of a species die.
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 community comes in contact with another.
- Pollution
- Hunting
Examples
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| Orthoceras lived until 485 million years ago. When the oceans became too cold it became extinct | The Woolly Mammoth became extinct when it lost its habitat at the end of the last Ice Age 10,000 years ago. | Haast's Eagle was the biggest eagle to ever exist, but it became extinct when humans killed all of its prey. |
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| The Dodo lived on a small island with no predators to kill it. When humans arrived, rats came with them and ate all the dodo eggs making them extinct. | 272 million years ago the atmosphere became polluted with 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 community comes in contact with another.
- Pollution
- Hunting
Mass Extinctions
When a community of many different species become extinct it is known as a mass extinction. Since life began on Earth there have been 5 great 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 nutrients 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 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 mammals.
- ... Some scientists believe we are in the middle of another mass extinction caused by humans because around 200 species are going extinct every day.