Earth has undergone billions of years of development since its birth, and today humanity has been able to become the supreme ruler on the planet. In the course of hundreds of millions of years of biological evolution, the earth has experienced the continuous evolution of species and the mass extinction of species. When we talk about species extinction, it is easy to think of the mass extinction of dinosaurs hundreds of millions of years ago. And this is even more distant from our time. In fact, among the thousands of biological groups on The Earth, species extinctions continue to occur as human activities continue to deepen.
Survey research by the World Wide Fund for Nature (WWF) shows that about 10,000 animal species on Earth go extinct every year, and the number of endangered animal species is even more numerous. The exact number of species extinctions on earth each year is difficult to count, and the reasons for this are extremely complex.
Some species were once extinct in one area, thought to have been extinct, but survived in other unknown areas and have since been rediscovered. And this "resurrection" may have been discovered and recorded, or perhaps no one knows about it.
Earth originated 4.6 billion years ago, and earthly organisms have experienced six mass extinctions in the course of evolution. About 50% of the fauna species went extinct at the end of the Cambrian period 500 million years ago; 350 million years ago, 30% of the fauna disappeared, including many jawless fish and shieldfish; 250 million years ago, at the end of the Permian, about 40% of the fauna species went extinct; the formation of dead trees in the coalfields of modern life began to occur in that period; 185 million years ago, 80% of reptiles disappeared; 65 million years ago, in the Cretaceous, dinosaurs suffered the ultimate mass extinction; and at the beginning of the Pleistocene 10,000 years ago, In particular, island-type species, large mammals and birds have become extinct.
The six extinctions mentioned above are largely caused by natural disasters, asteroid impacts, and climate change; however, since the first industrial revolution in the mid-18th century, the extinction of Earth's species due to the influence of human activities has become increasingly prominent. For example, many animal species such as the Icelandic auk, the North American passenger pigeon, the Indonesian Balinese tiger, the Australian thylacine, the straight-awi macaque, the high-nosed antelope, the Taiwanese clouded leopard and many other animal species have disappeared forever.
The Waldron red colobus monkey, alias Miss Watton red colobus monkey, was considered extinct about 10 years ago. They live on the border of Ghana and Côte d'Ivoire in Africa and are characterized by the absence of a thumbs up. This population of red colobus monkeys has a mild temperament and lives in groups, usually living in huge tree canopies in dense forests.
As the primary forests on which they depend are rapidly reduced by humans, the living habits of these rare monkeys are forced to change, and they are more vulnerable to natural predators and poachers, and inbreeding leads to the intensification of genetic defects, which eventually leads to extinction.
The African Zanzibar red colobus monkey is one of the close relatives of Miss Walton's red colobus monkey and one of Africa's rarest endangered primates, with fewer than 1,500 currently numbering. A quarter of the species currently listed on WWF's Endangered Species list includes more than a thousand species of birds and tens of thousands of plant species.
Let's take a look at some of the animals that have disappeared forever and are temporarily extinct. Baiji dolphin, also known as white-tipped dolphin, white-tipped dolphin, white-tipped whale, white-tipped, white-tipped, white-tailed, green-finned, Jiangma, Yangtze porpoise, Chinese finless porpoise and Yangtze River pufferfish, are unique freshwater dolphins in China, which are only produced in the middle and lower reaches of the Yangtze River. In 2006, the baiji dolphin was declared extinct. Studies have shown it to be one of the oldest freshwater mammals in the world.
Although the appearance of the baiji dolphin does not seem to be as smooth and elegant as that of dolphins, its sonar positioning system is highly developed, and it is unbeatable in the dolphin family, because it can accurately lock the position of a fish.
However, this superiority has become the murderer of them, with the continuous development of China's economy, the Yangtze River shipping industry has become more and more developed. The pollution of the water environment caused by the dense concentration of fishing boats, container ships, trawlers and various human activities in cities along the river makes the highly sensitive baiji dolphin intolerable, difficult to survive and eventually extinct.
Caribbean monk seals have been frequented in the Gulf of Mexico, the east coast of Central America and the northern coast of South America. Because their fat can be refined from seal oil, they have encountered excessive hunting in the past. At the same time, the fish and shrimp marine life on which they depend is becoming increasingly scarce due to human overfishing.
The number of Caribbean monk seals plummeted in numbers in the middle of the last century, and was last discovered by humans in 1952 on the small island of Serana in the Western Caribbean, between Jamaica and Nicaragua.