There are no more dinosaurs living on Earth. One time, there used to be dinosaurs that wandered the Earth. About 65 million years ago, though, most scientists believe that all of the dinosaurs disappeared, as well as most of the species that existed at that time. A species is a certain group of living organisms, like dinosaurs, humans, birds, and many others. They believe the loss of the organisms occurred due to a large asteroid colliding with Earth, which caused the extinction of many of the organisms.
Extinction means there is no longer a plant or animal species of a certain kind living anywhere in the world. The species that becomes extinct has died out. The dinosaurs were one of those species, along with others that died out 65 million years ago.
Extinction, though, usually occurs over a long period of time, but when it does happen at a faster rate, it is called mass extinction.
There are also species that have become extinct when they lose the ability to adapt to changes in the environment. For example, if the climate changes over a period of time, a certain animal or plant may not be able to survive. Certain species also may not be able to survive if faced with new predators that may end up wiping out the entire species. Finally, extinction could occur to a plant or animal if they no longer have access to the food they need to live and survive. These types of extinction most often take place over a much longer period of time compared to mass extinction, which can take place very quickly. Either way, the species that become extinct do not return.
Humans can be the cause of extinction as well. There are several ways humans can cause the extinction of a certain plant or animal species. Humans may overhunt wiping out an entire animal species, which almost happened many years ago when the buffalo nearly became extinct. Humans were hunting them down for food, fur, and for other reasons. The buffalo were dying faster than they could be replaced through reproduction.
Humans may also be responsible for habitat destruction, which occurs when a plant or animal's environment is destroyed by development or construction, such as destroying parts of a rainforest. Another example is the moving of non-native species, into an area where they are not usually found. An example of this type of extinction occurred to the dodo bird. The dodo bird died out because it became food for non-native species such as pigs and cats, which were moved by humans into the dodo's habitat.
Today, blue whales are facing extinction due to humans overhunting them. The destruction of habitats, changes in climates, and other factors may also threaten many plants and insects throughout the world.
The types of animals and plants at a risk of becoming extinct are called endangered species. When a species is endangered, they may soon die out and no longer exist. Some endangered species today include the giant panda, mountain gorilla, black rhino, tiger and many others.
There will always be animals and plants that become extinct, but doing simple things like recycling, saving energy, planting a garden or sponsoring an endangered animal can help prevent extinction of some species in the world.
In summary, extinction can take place quickly like in a mass extinction, or may occur over a long period of time. There are many reasons different species become extinct.