Whether it is before the emergence of humans or after the emergence of humans, species extinction is occurring, and the reasons for their extinction are different. But scientists have discovered that species extinction is not without rules. Most species actually suffer from the same "disease" before they become extinct.

Species extinction: They all suffered from the same "disease"

There have been five mass extinctions of species on the earth, and each time more than 70% of species disappeared. Today, human beings are in the midst of the sixth mass extinction of species, which is unquestionable in the scientific community.

Relevant research shows that the temperature The rise in climate and environmental damage means that 1 million species on Earth are threatened with extinction in the next few decades.

However, the time span from emergence to extinction varies greatly for different species. The longest existence time is 160 million years, and the shortest one is only one million years, such as the primates where humans live.

In exploring the reasons for species extinction phenomenon, scientists discovered that most species suffered from the "disease" of "specialization" before going extinct.

Specialization of organisms refers to the evolution of unique characteristics by species in order to adapt to a specific environment. They are better at surviving in certain environments, but at the same time become less able to adapt to other environments.

The extinct West African black rhinoceros

For example, loaches, most of them live in fast-flowing rivers. They can cling to stones on the bottom of the river and survive faster than other fish in rapids. Have a greater survival advantage.

At the same time, the loach's gills have also become smaller, because strong currents help them obtain oxygen from the water flow.

However, when the environment encounters mutations, it is difficult for them to survive. For example, if a hydropower station is built in a river where loaches live and the flow rate is reduced, they may face the dilemma of dying from lack of oxygen.

Loach suckers

Not just loach suckers, there are many species on the earthSpecialized phenomenon. In the process of evolution, species, the environment, and other surrounding species influence and adapt to each other. Specialization allows them to survive and reproduce better in specific environments, but it also has its drawbacks: they are not adaptable to other environments.

"Symptoms" caused by specialization

The most common symptom caused by specialization is "reduced resistance", and species will show narrow temperature, food specialization, symbiosis and parasitism , characteristics such as excessive individual size, slow growth and development, and low reproductive rate.

Pinta Island Tortoise

If a species exhibits one or more of these characteristics, its chance of extinction is higher.

The typical representative of "narrow temperature" is the polar bear. They rely on the Arctic ice caps for their lives and have evolved white protective colors and fur that can keep warm. They mainly use Seals for food.

But when the earth's environment warms, ice caps may disappear in large numbers, food will also decrease, and hot weather will also reduce their chances of survival.

Polar Bear

The representative of "specialized food habits" is my country's national treasure, the giant panda. The giant panda is a carnivore, but during its long evolutionary process, its diet has changed from meat to vegetarian, and now it only eats bamboo, which is high in fiber and low in energy.

Different species have different degrees of specialization. The more highly specialized a species is, the easier it is to become extinct. This is exactly the case with giant pandas.

Once the food (bamboo) in the living area disappears on a large scale, the pandas will face the risk of starving to death.

The Wenchuan Earthquake caused a large number of bamboos to die. Wild giant pandas were in short supply of food and their reproduction was seriously affected, causing them to fall ill or die.

The impact of "excessive individual size" on organisms is well understood. Their large size helps them eat larger foods and reduces the chance of being attacked by other animals. If the environment is stable, then their survival advantage is obvious.

However, if the environment deteriorates and food decreases, it will be difficult for these large animals to survive because they require a lot of energy. In times of food scarcity, this is undoubtedly a fatal "shortcoming."

Pterosaurs

The representative of "low reproductive rate and slow growth and development" is the passenger pigeon. Passenger pigeons need to breed in a group, laying only one egg at a time, and then the group takes careful care of it. It is a model of "fewer births and better births" in the animal world.

However, once they are hunted and a very small number of their offspring disappear, and the passenger pigeon population cannot quickly replenish the missing number, they are prone to extinction.

Passenger Pigeon

In the 19th century, the number of passenger pigeons was very considerable, and it was one of the best among birds. However, in less than a hundred years, due to the large-scale hunting by humans, they had From billions to extinction.

Humans cannot stand by idly

If only one specialized symptom occurs, the impact may not be fatal, but if two or more occur, the species is in danger.

For example, giant pandas, with their single-minded eating habits and low reproductive rate, have turned themselves into endangered animals. If they were not protected as national treasures by our country and loved by people all over the world, their current situation would be very worrying. .

Human beings cannot turn a blind eye to endangered species. On the one hand, the ecological environment is a whole, and it affects the whole body. The disappearance of one or more species will bring about changes in the ecosystem. We cannot guarantee that these changes will be good.

Endangered species snow leopard

In the final analysis, protecting endangered species and the ecological environment is not for the sake of the earth and nature, but for the better survival and reproduction of mankind.

In addition, some people believe that the extinction of highly specialized species is due to their inability to adapt to the new environment and has nothing to do with humans. But in fact, humans cannot escape responsibility.

The white-tip dolphin is considered to be the first cetacean to go extinct due to human factors

Before the emergence of humans, the speed of environmental change was generally not fast, and many species had Time adapts to new environments through evolution;

After the emergence of humans, due to various activities, the speed of environmental changes has greatly accelerated, symptoms caused by species specialization appeared in advance, and their extinction speed also became faster .

The dodo became extinct due to human factors

In addition, some species did not face extinction after becoming specialized. It was human hunting that led to their disappearance, such as the passenger pigeon . In general, protecting specialized species is to protect humans themselves, and the endangerment of some species is partially due to humans, so we cannot turn a blind eye.