Why do animals become extinct?

Every day millions of users ask Google's famous search engine questions in various fields. These questions include: Why do animals become extinct?

One of the answers that Google boasts is that it is easy to point the finger at people when talking about the global extinction crisis. But the first thing about extinction is that it is not new and is not always human error.

"13% of all bird species, 25% of all mammals and up to 50% of amphibian species are threatened with extinction"
When you look at the great life classes in the rock layers, extinction is a common phenomenon in the history of life on Earth.

In fact, of all species preserved as fossils, 99.9% belong to extinct groups. That means, in a nutshell, that all life is extinct, says Professor Norman McLeod at the London Museum of Natural History.

So why is extinction so common? It is simply that species is replaced. They find competitors of new types crushed by factors such as starvation through competition or harsh life by storms, floods, drought, new diseases or - most often - through a combination of all these things.

In our present age, many extinctions are looming according to conservation science. According to the IUCN in 2016, 13% of all species of birds, 25% of all mammals and possibly up to 50% of amphibian species are currently threatened with extinction, even insects feel the same pressure.

As for the causes of these declines, the answer lies in habitat loss, overfishing, by-catch, desertification, illegal wildlife trade, illegal fishing, poisoning and invasive wildlife diseases, and other causes of the list.

Source: https://www.theguardian.com/commentisfree/2017/may/24/why-do-animals-go-extinct-google