Curious Kids: Do humans really need other species? | Kiowa County Press

Science shows that humans are happier and healthier around other animal and plant species. Artur Debate/Moment via Getty Images

Tom Langen, Clarkson University

curious children is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]


Can humans live without any other species of plants or animals? – Arunima S., 14, Chhindwara, Madhya Pradesh, India


People certainly cannot survive without other species.

As an environmentalist – a scientist who studies the interactions of plants, microorganisms, fungi and animals, including humans – I know there are at least three reasons why we need other organisms.

Humans need other species to produce food

First, without other species, people would have nothing to eat.

Humans and all organisms need food for energy and materials to build their bodies and reproduce. Only certain micro-organisms and plants have a means of use the energy of the sun, water and carbon dioxide to make the basic molecules that provide this nourishment. This process is called photosynthesis..

Without these organisms, humans would have no food to eat. Almost everything we eat is either a plant or other photosynthetic organism, an animal that browses on them, or an animal that eats animals that browse.

Processed foods may not appear to come from microbes, plants, fungi, or animals, but almost all of them are. Some vitamins and other food ingredients are manufactured, but they are a very small part of the human diet.

Chemists have discovered ways to use various sources of energy to make molecules that could be used for food. Molecules produced in this way are called “synthetics”. However, these processes are so difficult and expensive that it is currently impossible to feed people these synthetic foods.

Synthetic food production using genetically modified bacteria or cultured cell lines is gaining in importance. In the future, human nutrition may become somewhat less dependent on the consumption of plants and animals. Yet living organisms will remain an essential component of these foods.

It takes countless different organisms – large, small and microscopic – to create healthy soil and breathable air. Decompose and recycle waste. To purify water and prevent erosion. To break down toxic chemicals into harmless forms and convert other chemicals into food sources that other organisms need to grow and thrive.

And many of our food plants – over 1,200 species – depend on pollinators to produce the fruit or seed that humans and other animals eat. Pollination, the process that allows plants to reproduce, occurs when animals carry pollen from one plant to another. Bees are the main pollinators, but many other insects, birds, bats and other animals also carry pollen between plants.

Yellow, brown and green bird perched on a red flower.
Birds and other animals fertilize plants by carrying pollen between them, allowing them to produce fruits and seeds that humans eat. krisanapong detraphiphat / Moment via Getty Images

Animals of all sizes, from tiny ants to huge elephants, move seeds, spread plants that create healthy and productive ecosystems. Various species, from tiny microbes to huge vultures and sharks, break down dead organisms into chemicals that can be used to produce more food.

The number of species that contribute to creating every bite of the average meal is staggering.

The human body needs other species to stay healthy

Many functions of the human body itself rely on a complex and highly diverse ecosystem of microbial species that live on the skin and in the respiratory, digestive and reproductive systems. These bacteria, fungi and other microbes are called “microbiome.”

Each person has a unique personal microbiome to protect against infections, digest and extract nutrients from food and synthesize vitamins.

For example, the gut microbiota is important for breaking down food into usable energy and nutrients, and for converting other indigestible or toxic substances into forms that can be excreted.

This microbiome changes over the course of people’s lives depending on what they eat, what is around them, where they live, and their health. In fact, human bodies are made up of more bacterial cells than human cells.

Food and drugs strongly affect the 300 to 500 species of bacteria which are at the heart of a healthy intestinal ecosystem.

The microbiome also plays an important role in preventing infections. Many diseases are associated with microbial communities dominated by a few species. Some doctors transplant poo from healthy people to sick people to establish a healthy community of microbes and hopefully cure disease.

Humans are happiest around other species

Finally, research shows that people are healthier and more satisfied when they are around other species of plants and animals. They need experience sights, sounds, smells, feel and taste other organizations for mental and physical health. This drive is called “biophilia”, that is to say the love of living beings.

For example, seeing and hearing birds creates positive feelings. Two recent studies in Canada and Germany found that the more species of birds in a neighborhood, the happier people are. This may be due to the experience of the birds themselves or to a healthy environment, as indicated by the presence of birds.

In another Canadian experiment, researchers broadcast bird songs from hidden loudspeakers along hiking trails. People have reported that they felt more restored and were more satisfied about hiking when they heard a diversity of bird species than when they heard little or none.

Today, more than half of the world’s population lives in cities instead of the campaign. Thus, urban planners and landscape architects are exploring ways to include more green space and green infrastructure in the towns.

Research shows that when a city has diverse wildlife, large open green space and vegetation along streets and on buildings, people are more active, less stressed, healthier and happier. These conditions provide opportunities for people to experience and interact with other organismsas well as enjoying the other things that plants, animals and microbes do to make the environment healthy and pleasant.

Scientists now know that it takes thousands of species to sustain human life. Yet we are only just beginning to understand important roles that different species play in ecosystems, including urban ones. We still need to learn a lot more about why and how other species are necessary for human survival. And if people are to be successful at traveling long periods of time in space or establishing space colonies, we will need to understand what species we need to bring with us to survive and thrive.


Hello, curious little ones! Do you have a question you would like an expert to answer? Have an adult send your question to [email protected] Please let us know your name, age and the city where you live.

And since curiosity has no age – adults, let us know your questions too. We cannot answer all questions, but we will do our best.

The conversation

Tom Langenbiology teacher, Clarkson University

This article is republished from The conversation under Creative Commons license. Read it original article.

About Florence M. Sorensen

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