The causes of the old and recent extinction
The scientists witnessed five mass extinctions , And some scientists believe that we live the sixth extinction age ( The Recent Extinction ) , where the rate of the extinction is 40 times larger than the normal rate of the extinction .
The causes of old extinctions
The scientists postulated that the causes of old extinctions is due to the emission of the poisonous gases from the active volcanoes , the meteorite impacts with the Earth , And the onset of a long glacial age .
The causes of the recent extinction
Destroying the natural habitat causes the recent extinction , The tropical forests include about one third of the terrestrial living organisms , where each tree forms a shelter of more than 300 species of the living organisms .
So , cutting the forests trees destroy the habitat of these species , and drive them stray and homeless , The scientists estimate that we lose about 68 species of the trees every day .
Overhunting is considered one of the important causes of the extinction of the hundreds of the reptiles and the mammals species , Overhunting is hunting the wild animals with random unorganized way which exposed them to the extinction .
This is due to the increased rate of the interest in the animals skins and furs , The progressive development in the technology of hunting weapons , And the absence of the laws that control the wild animal hunting at the beginning of the 20 th century .
Environmental pollution causes the extinction of many living organisms , When the oil leaks in the oceans and the seas it causes the death of the marine birds , When the acidic rains fall they destroy the forests trees , And the chemical insecticides break down the food chains .
The climate changes and the natural disasters causes the recent extinction , Some of disasters are related to the climatic changes such as the drought , the tornadoes , the floods , the lightning , the torrents , the storms , And rising the temperature of the Earth planet .
There are some disasters that are not related to the climate changes such as the earthquakes , the volcanoes and the high marine tide ( the tsunami waves ) , Natural disasters are considered one of the causes that leads to the extinction of the species .