Extinction

Key Stage 3

Extinction is when all the members of a species die.

Extinction can be caused by a number of factors:


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.

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.

Extinction is when all of the members of a species have died.

Extinction can be caused by a number of factors:

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.