Human uses of living things, including animals, plants, fungi, and microbes, take many forms, both practical, such as the production of food and clothing, and symbolic, as in art, mythology, and religion. Social sciences including archaeology, anthropology and ethnography are starting to take a multispecies view of human interactions with nature, in which living things are not just resources to be exploited, practically or symbolically, but are involved as participants.
Plants provide the greater part of the food for people and their domestic animals: much of civilisation came into being through agriculture. While many plants have been used for food, a small number of staple crops including wheat, rice, and maize provide most of the food in the world today. In turn, animals provide much of the meat eaten by the human population, whether farmed or hunted, and until the arrival of mechanised transport, terrestrial mammals provided a large part of the power used for work and transport. A variety of living things serve as models in biological research, such as in genetics, and in drug testing. Until the 19th century, plants yielded most of the medicinal drugs in common use, as described in the 1st century by Dioscorides. Plants are the source of many psychoactive drugs, some such as coca known to have been used for thousands of years. Yeast, a fungus, has been used to ferment cereals such as wheat and barley to make bread and beer; other fungi such as Psilocybe and fly agaric mushrooms have been gathered as psychoactive drugs.
Many species of animal are kept as pets, the most popular being mammals, especially dogs and cats. Plants are grown for pleasure in gardens and greenhouses, yielding flowers, shade, and decorative foliage; some, such as cactuses, able to tolerate dry conditions, are grown as houseplants.
Animals such as horses and deer are among the earliest subjects of art, being found in the Upper Paleolithic cave paintings such as at Lascaux. Living things play a wide variety of symbolic roles in literature, film, mythology, and religion. Sometimes a major disease like tuberculosis is depicted in art and literature, in its case being associated for some reason with artistic creativity.
Scope
Scholars have traditionally divided uses of animals, plants, and other living things into two categories: practical use for food and other resources; and symbolic use such as in art and religion. More recently, scholars have added a third type of interaction, where living things, whether animals, plants, fungi or microbes function as participants. This makes the relationships bidirectional, explicitly implying various forms of symbiosis in a complex ecology. These three types are described in turn.
Practical uses
For food and materials
The human population exploits and depends on many animal and plant species for food, mainly through agriculture, but also by exploiting wild populations, notably of marine fish. Livestock animals are raised for meat across the world; they include (2011) around 1.4 billion cattle, 1.2 billion sheep and 1 billion domestic pigs.
Plants provide the greater part of food for humans, and for their domestic animals. They have played a key role in the history of world civilizations. Agriculture includes agronomy for arable crops, horticulture for vegetables and fruit, and forestry for timber. About 7,000 species of plant have been used for food, though most of today's food is derived from only 30 species. The major staples include cereals such as rice and wheat, starchy roots and tubers such as cassava and potato, and legumes such as peas and beans. Vegetable oils such as olive oil provide lipids, while fruit and vegetables contribute vitamins and minerals to the diet.
Plants grown as industrial crops are the source of a wide range of products used in manufacturing, sometimes so intensively as to risk harm to the environment. Nonfood products include essential oils, natural dyes, pigments, waxes, resins, tannins, alkaloids, amber and cork. Products derived from plants include soaps, shampoos, perfumes, cosmetics, paint, varnish, turpentine, rubber, latex, lubricants, linoleum, plastics, inks, and gums. Renewable fuels from plants include firewood, peat and other biofuels. The fossil fuels coal, petroleum and natural gas are derived from the remains of aquatic organisms including phytoplankton in geological time. Structural resources and fibres from plants are used to construct dwellings and to manufacture clothing. Wood is used not only for buildings, boats, and furniture, but also for smaller items such as musical instruments and sports equipment. Wood is pulped to make paper and cardboard. Cloth is often made from cotton, flax, ramie or synthetic fibres such as rayon and acetate derived from plant cellulose. Thread used to sew cloth likewise comes in large part from cotton. Plants are a primary source of basic chemicals, both for their medicinal and physiological effects, and for the industrial synthesis of a vast array of organic chemicals. Note that the details of each plant and the chemicals it yields are described in the linked subpages.
Textiles are made from both animal fibres, including wool and silk, and plant fibres, including cotton and flax. Dyestuffs too are made both from animals, including carmine from the bodies of insects, from plants including indigo and madder, and from lichens.
For work and transport
Working domestic animals including cattle, horses, yaks, camels, and elephants have been used for work and transport from the origins of agriculture, their numbers declining with the arrival of mechanised transport and agricultural machinery. In 2004 they still provided some 80% of the power for the mainly small farms in the third world, and some 20% of the world's transport, again mainly in rural areas. In mountainous regions unsuitable for wheeled vehicles, pack animals continue to transport goods.
In science
Biology studies the whole range of living things. Animals such as the fruit fly Drosophila melanogaster, the zebrafish, the chicken and the house mouse, serve a major role in science as experimental models, both in fundamental biological research, such as in genetics, and in the development of new medicines, which must be tested exhaustively to demonstrate their safety. Millions of mammals, especially mice and rats, are used in experiments each year. Knockout mice are used to help discover the functions of genes.Y Zan et al., Production of knockout rats using ENU mutagenesis and a yeast-based screening assay, Nat. Biotechnol. (2003).
Basic biological research has been done with plants. In genetics, the breeding of pea plants allowed Gregor Mendel to derive the basic laws governing inheritance, and examination of chromosomes in maize allowed Barbara McClintock to demonstrate their connection to inherited traits. The plant Arabidopsis thaliana is used in laboratories as a model organism to understand how genes control the growth and development of plant structures. Space stations or space colonies may one day rely on plants for life support.
For medicines and drugs
Vaccines have been made using animals and microbes since their discovery by Edward Jenner in the 18th century. He noted that inoculation with live cowpox afforded protection against the more dangerous smallpox. In the 19th century, Louis Pasteur developed an attenuated (weakened) vaccine for rabies. In the 20th century, vaccines for the viral diseases mumps and polio were developed using animal cells grown in vitro.
An increasing variety of medicinal drugs are based on toxins and other molecules of animal origin. The cancer drug Yondelis was isolated from the tunicate Ecteinascidia turbinata. One of dozens of toxins made by the deadly cone snail Conus geographus is used as Prialt in pain relief.
Since classical times and possibly much earlier, hundreds of species of plants have provided drugs to treat a wide range of conditions. Dioscorides's De Materia Medica, written by 70 AD, listed some 600 medicinal plants and around 1000 drugs made from them, including substances known to be effective such as aconite, aloes, colocynth, colchicum, henbane, opium and squill. The book remained a standard reference for nearly two thousand years, and was the basis of the European pharmacopoeia until the end of the 19th century.
Also since the earliest times, people have exploited some of the many psychoactive substances manufactured by plants in religious rituals and for pleasure. Among the most widely used throughout history are alcohol, produced by fermenting cereals with yeast (a fungus), tobacco, coffee, tea, chocolate, cannabis, coca (used as leaf for some 8,000 years in Peru,Early Holocene coca chewing in northern Peru Volume: 84 Number: 326 Page: 939–953 and in recent times also purified to cocaine), mescaline (from a cactus) and psilocybin (from a fungus).
For pleasure
Both animals and plants are used to provide pleasure, through a range of activities including keeping pets, hunting, fishing, and gardening.
A wide variety of animals are kept as pets, from invertebrates such as tarantulas and octopuses, insects including praying mantises, reptiles such as snakes and chameleons, and birds including canaries, parakeets and parrots all finding a place. Mammals are the most popular pets in the Western world, with the most kept species being dogs, cats, and rabbits. For example, in America in 2012 there were some 78 million dogs, 86 million cats, and 3.5 million rabbits. There is a tension between the role of animals as companions to humans, and their existence as individuals with rights of their own.
Many animals are hunted for sport. The aquatic animals most often hunted for sport are fish, including many species from large marine predators such as sharks and tuna, to freshwater fish such as trout and carp. Birds such as partridges, pheasants and ducks, and mammals such as deer and wild boar, are among the terrestrial game animals most often hunted. Chapters on hunting deer, wild hog (boar), rabbit, and squirrel.
Thousands of plant species are cultivated for aesthetic purposes as well as to provide shade, modify temperatures, reduce wind, abate noise, provide privacy, and prevent soil erosion. Plants are the basis of a multibillion-dollar per year tourism industry, which includes travel to historic gardens, national parks, rainforests, forests with colourful autumn leaves, and festivals such as Japan's and America's cherry blossom festivals. While some gardens are planted with food crops, many are planted for aesthetic, ornamental, or conservation purposes. Arboretums and botanical gardens are public collections of living plants. In private outdoor gardens, lawn grasses, shade trees, ornamental trees, shrubs, vines, herbaceous perennials and bedding plants are used. Gardens may cultivate the plants in a naturalistic state, or may sculpture their growth, as with topiary or espalier. Gardening is the most popular leisure activity in the U.S., and working with plants or horticulture therapy is beneficial for rehabilitating people with disabilities. Plants may also be grown or kept indoors as houseplants, or in specialized buildings such as greenhouses that are designed for the care and cultivation of living plants. Venus Flytrap, sensitive plant and resurrection plant are examples of plants sold as novelties. There are also art forms specializing in the arrangement of cut or living plant, such as bonsai, ikebana, and the arrangement of cut or dried flowers. Ornamental plants have sometimes changed the course of history, as in tulipomania.
Symbolic uses
In art
Both animals and plants are significant in art, whether as background or as main subjects.