Human beings are guilty of the disappearance of many animal species and the destruction of the environment. Despite the constant alerts and the call for attention from scientists, the issue never gains the importance it deserves.

The vital question remains what would be the consequence if we woke up one day without any animals on Earth. Several recent studies explain why the loss of animal species is perhaps one of the most severe ecological issues, perhaps even more serious than global warming.

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Results of Scientific Study

Why are thousands of species facing extinction? | Video Credit – BBC

According to the estimates of the World Resource Institute with the UNEP, between 150 and 200 wild species disappear every day. Knowing that there are around 100 million living animal species on earth (according to the highest estimates), this means that we could destroy absolutely all of the animal biodiversity on the planet in less than 1,500 years (i.e., less than 0.5% of the time that Homo Sapiens has existed).

A WWF study estimated that over the past 40 years, 60% of the planet’s animals have disappeared (among the populations of the 3706 vertebrate species monitored by WWF). So one could argue that biodiversity is constantly fluctuating: this is one of the principles of evolution. At certain times, species disappear, others appear, and some evolve. 

But what is worrying today is that the rate of loss of biodiversity is about 1000 times the rate customarily observed. It is the fastest extinction rate since the dinosaurs became extinct 65 million years ago.

We do not realize these disappearances since most of them are not publicized. The vast majority of species that disappear are insects, small animals, birds, and plants, and unfortunately, this is less selling in the media than the disappearance of large mammals. Sometimes, it is even species that we had not even identified yet that disappear.

If There Are No Animals

What If There Were No Animals On Earth?

The normal functioning of terrestrial ecosystems is based mainly on the diversity of life forms that compose them. In other words, every species participates in one way or another in the functioning of the global ecosystem. 

We could say that they all play a role in the “balance” of ecosystems. However, if they disappear, this role is no longer assured, and this disrupts the overall functioning, which inevitably has consequences for humanity.

1. Human Extinction

Image of Human Extinction
Image of Human Extinction | Image Credit – The Independent

According to Gonzalo Andrade, director of the Institute of Natural Sciences of the National University of Colombia and member of the Colombian Academy of Exact and Natural Sciences, the disappearance of wild animal life would mean a complete imbalance of the life on earth, and it would represent a danger of life extinction as we know it.

A study published in Nature in 2016 shows that the more biodiverse an ecosystem, the more nutritionally productive it is. In summary: the more animal, plant, fungal, or insect species there are in an environment, the greater the capacity of this environment to transform static and mineral resources into living and organic resources. 

To put it simply: plants convert minerals into organic matter, they are themselves converted into denser and more complex nutrients by herbivorous species, and so on. And the more different plants, insects, and animals there are, the more varied and efficient this conversion is. 

The species diversity also contributes to maintaining the nutritional qualities of soils and, therefore, ensuring the sustainability of the reproduction of the different species. 

In summary: the less biodiversity there is, the less efficient ecosystems are in producing nutrients that humans can consume. The best-known example is pollinating insects: without them, the development of fruits or vegetables is difficult.

2. Absence of Nutrient cycling and decomposition

Plants need nutrients to grow and produce seeds and fruit. Trees look for these nutrients in leaves that have fallen on the soil surface, deadwood, and branches, all of which are rich in carbon and nutrients. Nutrients are removed by the trees from the ground and then returned to the land through decomposing the residues. There is a continuous transfer of nutrients from the soil to the plants and from these to the soil. 

This process is called “Nutrient Cycling” and requires decomposing animals, such as microorganisms and invertebrates. They break leaves and branches into tiny particles. Therefore, there is no organic decomposition or nutrient cycling without invertebrate and vertebrate animals.

3. Increase in forest fires

Forest fire
Forest fire | Image Credit – Flickr

A forest fire is a bad news because of the danger it represents for the nearby communities. They are difficult to control and take ecosystems, wildlife, and the possibility that life will germinate there as it used to. Now imagine the result of hundreds of fires around the world.

According to the journal Science Advances, the disappearance of large herbivore species would also lead to a debacle, as they carry out the work of “gardeners” in the ecosystems they inhabit. The disappearance of the world’s largest herbivores would mean an increase in weeds and a concentration of biomass not consumed, increasing the risk and severity of forest fires.

A scientific meta-analysis also explains that biodiversity is a factor of stability for ecosystems. The more an ecosystem has varied biodiversity, the more it resists “hazards.” When biodiversity decreases, environments are less resilient and more vulnerable because they are less “dense.” 


4. Depletion of air and water quality

Image of Depleted air and water quality
Image of Depleted air and water quality | Image Credit – Flickr

A wide range of fauna and flora would also promote air quality and water quality. Whether through the plant or microbial world, the fungi varieties, or even the different animals and insect species, biodiversity and nature act as filters for our environment. 

The air quality we breathe, for example, depends on biodiversity. On the one hand, the oxygen we breathe is produced by living species (bacteria, plankton, and plants). The first producer of oxygen on the planet is plankton and oceanic phytoplankton. When marine biodiversity decreases, it affects plankton and its ability to produce oxygen—ditto with the trees of the Amazonian forests. In terms of water quality, it’s the same.

5. Evolution would stop

If we imagine a scenario in which even parasites leave the earth and leave us to our fate, the scene would be dark since they serve to keep pests at bay both in our homes and in our crops, but it would also dramatically halt evolution.

According to National Geographic, we need to save parasites for good health. Eliminating all parasites means promoting autoimmune diseases. When in the pandemic of COVID 19, everyone is talking about the human immune system; we tend to forget that the immune system developed due to worms and protozoans.

If we kill them, our immune system will start attacking our bodies. Some species of animals will become extinct, while some will explode. How soon it happens or not, however, is not what worries scientists, but the imminence that without animals, the planet cannot exist.

6. Adverse Effect on Health of Humanity 

Plant and animal extinction is related to the increase in infectious diseases in humans. Researchers in the United States have found that the most sensitive species and, therefore, more exposed to changes in their environment help slow the spread of certain infectious diseases.

On the contrary, those more resistant to contamination usually have a greater capacity to transmit microorganisms to other living beings, including people. Bacteria, viruses, and fungi, the primary producers of diseases, are adapted to live and survive in a specific niche. As long as that niche exists, bacteria and viruses will live in a perfect symbiosis.

Bacteria, viruses, and fungi do not resign themselves to becoming extinct together with the organism that hosts them, and they increase their genetic variability to conquer new hosts. Therefore, genetic diversity is essential for the development of all species, and human beings depend on it in their daily lives.

“Indirectly, changes in an ecosystem affect livelihoods, income, and local migration, and can sometimes even cause social conflict,” according to the WHO (World Health Organization)report. When there are no animals, such genetic biodiversity decreases, and human life expectancy is reduced from an ecological and a resource point of view, even to have species adapted to an ecological niche.

For example, we need to have animals – like cows – adapted to different climate types. Biodiversity is transcendental in every way. The WHO notes that, in addition, “the biophysical diversity of microorganisms, flora, and fauna offers extensive knowledge that entails important benefits for biology, health sciences, and pharmacology.”

In nature, we need to have a lot of biodiversities to find new antibiotics and new molecules that help us fight diseases, for example. In short, we also need it from the view of utility.

7. No Mosquitoes, No Ecosystem

Mosquitoes are tough insects to kill, and killing many mosquitoes will have little effect on humans. Humans have tried to eradicate mosquitoes using chemicals, but things like DDT (organochlorine pesticides) have become very harmful to the planet and humans.

However, killing all mosquitoes will only aggravate our problems. Scientists argue that certain species of mosquitoes play a significant role in the environment. Mosquitoes in the Arctic Circle of Canada and Russia fly around in clusters, forming part of enormous biomass. It pollinates plants in the Arctic and is the primary food source for migratory birds.

Eliminating these northern mosquitoes, or the species of mosquitoes that feed by fish, birds, and other insects in the south, can tear the ecosystem and endanger many other plants and animals. So it’s best not to kill all the mosquitoes. Nor is it necessary. We know what kind of mosquitoes infect and transmit the worst viruses and parasites in humans.

Many researchers are currently developing ways to target these mosquitoes to kill the mosquitoes themselves and the dangerous diseases they carry.

8. Unbalance in Nature without birds

Image of World without Birds
Image of World without Birds | Image Credit –

Environments such as forests, marshes, and grasslands affect people on the planet, including those who live hundreds of miles away. These environments store carbon, stabilize the climate, send oxygen to the atmosphere, and turn pollutants into nutrients. But without the presence of birds, many of these ecosystems would not exist. 

Birds maintain a delicate balance between plants and herbivores, predators and prey. One of the best examples is the saltwater marsh in the southeastern United States which filters water and protects the coast from sea erosion. Seawater snails eat many of these marshes, but without oystercatchers, whimbrels, and plovers, these little shellfish will eat up the entire marsh and leave only tidal flats.

9. No science and Beauty without Animals

If human life expectancy has taken a giant leap in the last century, a good part of this victory is due to animals. They are at the forefront of numerous scientific studies, testing drugs and treatments before being evaluated in people. 

Despite going hand in hand with human political and social development, the most intensive tests on animals took place at the beginning of the 20th century, in the first treatments against rabies and leprosy, for example. 

Scientists and researchers found that some animals share genetic similarities with humans. It would be easier and less dangerous to test substances of all kinds on them to ensure the user’s safety later. Medicines are first tested on rats and mice to determine if the quantity of that dose will not cause any damage to the organism of the rat and mouse. 

Then the medicine is tested on bigger animals such as dogs. Once the dose is tested safely on the dog, then the test is conducted on human beings. Before introducing to the market for human use, medicine and any cosmetic products are tested on animals.

Before being in our skin, they or the substances that make them up may have passed through some animals’ epidermis, mouth, and even eyes, which serve as guinea pigs to analyze their effects on humans. But far from being a simple use of products as we do at home, these studies are designed to observe adverse reactions. Such as what happens if some substances come into contact with the eyes. 

One of the tests used on animals, which emerged in the 1940s, was the ‘Draize Test.’ It assesses substances’ ocular irritability and a degree in an animal model such as rabbits. The primary purpose of cosmetic animal testing is to anticipate some of the substance’s reactions in humans, including effects such as rash, eye irritation, and skin burns. If there were no animals, we might not have antibiotics, syrups, vaccines, lipsticks, deodorants, or perfumes. 

10. Without Animals, there may be no new Invention

For centuries, people have watched the wonders of nature and got ideas for their inventions. So even a separate science appeared – bionics, and its subsection – biomimetics, which is based on the principle of borrowing ideas and essential elements from animals for new technologies.

Some inventions and technologies inspired by animals are:

I. Road Reflectors

The cat has become a natural muse for the Englishman Percy Shaw. Once he paid attention to how car headlights are reflected in the cat’s eyes, he came up with the first road reflectors, which we can now find everywhere.

II. Light and bioluminescence

Long before the invention of candles and night lights by man, many animals and even some types of fungi used bioluminescence. Some scientists are trying to find the possibility of its application in the modern world; others have focused on fireflies and have already achieved success. They managed to recreate the light emitted by the glowing organs of these miraculous insects. The resulting LED is 55% brighter than the original.

III. Cloning

Cloning | Image Credit – National Geography

When it comes to cloning, the real expert is the starfish. When people still could not think about the possibility of such a process, the starfish reproduced independently and without much difficulty. Moreover, a starfish that creates clones is healthier and lives much longer than a starfish that reproduces sexually, and their clones are not subject to the aging process. Who knows, maybe someday these starfish will give us the secret of eternal youth.

IV. Sonar

Sonars were donated by nature to whales and dolphins, thanks to which they navigate underwater, find differences between objects from a distance of 15 meters, look for food, and even friends. Submarines, ships, and other marine vessels are equipped with the same sonars for navigation, target tracking, and obstacle avoidance. Sound waves bounce off solid objects in the ocean and return to the sonar, which provides information about the surrounding objects.

V. Robotic Arm

Robotic Arm
Robotic Arm | Image Credit – Flickr

The ability of the elephant’s trunk to stretch in any direction and grab whatever it wants was used by scientists when developing a robotic arm. It consists of a plastic tube that acts as a spine and 4 “fingers” that make the hand more dexterous. These incredible animals inspire many more such incredible inventions and technologies. Had there been no animals, these inventions would not have been possible. 

11. No Economy without Insects

No Economy without Insects
No Economy without Insects | Image Credit – Flickr

Although insects are tiny creatures, they largely contribute to the planet’s economy. According to National Geographic, insects contribute about $ 57 billion to the US economy. Much of this economy comes from the wildlife we consume. They depend on insects for food. The rest of the finances come from pest control, pollination, and manure burial.

Insects also play an essential role in medicine. For example, bee honey is used to treat burns and skin conditions, Brazilian wasp venom can kill cancer cells, and larvae are used in larval therapy to treat incurable wounds.

Without insects, the economy is affected, and the world would not have access to such a necessary treatment for diseases. According to the FAO, at least two billion people use insects worldwide. Without insects, humans would lose another source of food. Until the end, there would be nothing left for animals and humans to eat.

12. Excessive tree cutting and war conflicts

Excessive tree cutting and war conflicts
Excessive tree cutting and war conflicts | Image Credit – Flickr

Logging trees will be more rampant because of the lack of food needs; humans will increase their agricultural land area into forests to increase their needs because not only 1 or 2 humans live on this earth, but millions of people. Humans are greedy; war will occur because of fighting over land for agriculture.

13. Rise of cannibalism

Rise of cannibalism
Rise of cannibalism | Image Credit – Wikimedia Commons

Humans will form a group in each area due to the lack of food, which only comes from agricultural products. Therefore humans will fight over areas with abundant food sources destroying peace on earth. Due to the lack of food, humans can eat their friends to survive and eat other humans due to wars fighting over territory.

14. New Pandemic will emerge

New Pandemic will emerge
New Pandemic will emerge | Image Credit – Flickr

Scientists warn that new deadly pandemics may occur due to rapid deforestation and reduced biodiversity. Scientists presented new evidence suggesting that the destruction of the environment is directly related to new epidemics such as the Covid-19 epidemic. Almost a third of emerging diseases result from changes in land use. As a result, scientists say that there may be five or six new pandemics that will affect the world population each year.

Professor Stuart Pimm, a wildlife conservationist at Duke University, told The Observer: “There’s so much activity now. Illegal logging, open space, mining. These are linked to international wildlife meat and exotic pet farming and are the causes of this crisis. The Covid-19 pandemic has cost the global world trillions of American dollars and killed almost a million people. Urgent action is needed.”

It is evaluated that millions of hectares of rainforest and natural habitat are destroyed by bulldozers each year to plant palm trees, create cattle ranches, extract oil, and gain access to mines and mineral deposits. It, in turn, causes the destruction of vegetation and natural life, where there are countless viruses and bacteria, most of which are not yet scientifically identified. These microbes can then accidentally infect new habitats, such as humans.

These events are known as ‘relocations.’ If viruses develop on new ‘hosts’ humans, they can infect other individuals. It is called ‘contamination’ and results in the emergence of new diseases. An example of this is HIV. HIV was transmitted to men and women in the early 20th century from chimpanzees and gorillas slaughtered for wild animal meat in West Africa, resulting in more than 10 million deaths.


That’s the impact that would happen if animals never existed on earth. We should be grateful to our God for the abundant food source throughout the planet, and Peace still exists. Therefore, to maintain food sources for humans, we need to maintain green plants and livestock so that they do not become extinct on earth. 

(Last Updated on May 18, 2022 by Sadrish Dabadi)

Ankur Pradhan holds a bachelor’s degree in education and health and three years of content writing experience. Addicted to online creative writing, she puts some of what she feels inside her stormy heart on paper. She loves nature, so she is trying to motivate people to switch to alternative energy sources through her articles.