Domestication
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Domestication is a multi-generational mutualistic relationship in which an animal species, such as humans or leafcutter ants, takes over control and care of another species, such as sheep or fungi, to obtain from them a steady supply of resources, such as meat, milk, or labor. The process is gradual and geographically diffuse, based on trial and error. Domestication affected genes for behavior in animals, making them less aggressive. In plants, domestication affected genes for morphology, such as increasing seed size and stopping the shattering of cereal seedheads. Such changes both make domesticated organisms easier to handle and reduce their ability to survive in the wild. The first animal to be domesticated by humans was the dog, as a commensal, at least 15,000 years ago. Other animals, including
goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...
s, sheep, and cows, were domesticated around 11,000 years ago. Among birds, the
chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...
was first domesticated in East Asia, seemingly for cockfighting, some 7,000 years ago. The horse came under domestication around 5,500 years ago in central Asia as a working animal. Among
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s, the silkworm and the
western honey bee The western honey bee or European honey bee (''Apis mellifera'') is the most common of the 7–12 species of honey bees worldwide. The genus name ''Apis'' is Latin for 'bee', and ''mellifera'' is the Latin for 'honey-bearing' or 'honey-carrying', ...
were domesticated over 5,000 years ago for
silk Silk is a natural fiber, natural protein fiber, some forms of which can be weaving, woven into textiles. The protein fiber of silk is composed mainly of fibroin and is most commonly produced by certain insect larvae to form cocoon (silk), c ...
and
honey Honey is a sweet and viscous substance made by several species of bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the sugary secretions of pl ...
, respectively. The domestication of plants began around 13,000–11,000 years ago with
cereal A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...
s such as
wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...
and
barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...
in the
Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...
, alongside crops such as lentil, pea, chickpea, and
flax Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. In 2022, France produced 75% of t ...
. Beginning around 10,000 years ago, Indigenous peoples in the Americas began to cultivate
peanut The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), goober pea, pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds. It is widely grown in the tropics and subtropics by small and large ...
s, squash,
maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...
, potatoes,
cotton Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...
, and
cassava ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...
.
Rice Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...
was first domesticated in China some 9,000 years ago. In Africa, crops such as
sorghum ''Sorghum bicolor'', commonly called sorghum () and also known as great millet, broomcorn, guinea corn, durra, imphee, jowar, or milo, is a species in the Poaceae, grass genus ''Sorghum (genus), Sorghum'' cultivated for its grain. The grain i ...
were domesticated. Agriculture developed in some 13 centres around the world, domesticating different crops and animals. Three groups of insects, namely ambrosia beetles, leafcutter ants, and fungus-growing termites have independently domesticated species of fungi, on which they feed. In the case of the termites, the relationship is a fully obligate symbiosis on both sides.


Definitions

Domestication (not to be confused with the taming of an individual animal), is from the
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
', 'belonging to the house'. The term remained loosely defined until the 21st century, when the American archaeologist Melinda A. Zeder defined it as a long-term relationship in which humans take over control and care of another organism to gain a predictable supply of a resource, resulting in mutual benefits. She noted further that it is not synonymous with agriculture since agriculture depends on domesticated organisms but does not automatically result from domestication. Michael D. Purugganan notes that domestication has been hard to define, despite the "instinctual consensus" that it means "the plants and animals found under the care of humans that provide us with benefits and which have evolved under our control." He comments that insects such as
termite Termites are a group of detritivore, detritophagous Eusociality, eusocial cockroaches which consume a variety of Detritus, decaying plant material, generally in the form of wood, Plant litter, leaf litter, and Humus, soil humus. They are dist ...
s, ambrosia beetles, and leafcutter ants have domesticated some species of
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
, and notes further that other groups such as weeds and commensals have wrongly been called domesticated. Starting from Zeder's definition, Purugganan proposes a "broad" definition: "a coevolutionary process that arises from a mutualism, in which one species (the domesticator) constructs an environment where it actively manages both the survival and reproduction of another species (the domesticate) in order to provide the former with resources and/or services." He comments that this adds niche construction to the activities of the domesticator. Domestication syndrome is the suite of phenotypic traits that arose during the initial domestication process and which distinguish crops from their wild ancestors. It can also mean a set of differences now observed in domesticated mammals, not necessarily reflecting the initial domestication process. The changes include increased docility and tameness, coat coloration, reductions in tooth size, craniofacial morphology, ear and tail form (e.g., floppy ears), estrus cycles, levels of adrenocorticotropic hormone and neurotransmitters, prolongations in juvenile behavior, and reductions in brain size and of particular brain regions.


Cause and timing

The
domestication of animals The domestication of vertebrates is the mutual relationship between vertebrate animals, including birds and mammals, and the humans who influence their care and reproduction. Charles Darwin recognized a small number of traits that made domestica ...
and plants was triggered by the climatic and environmental changes that occurred after the peak of the
Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago. Ice sheets covered m ...
and which continue to this present day. These changes made obtaining food by hunting and gathering difficult. The first animal to be domesticated was the dog at least 15,000 years ago. The Younger Dryas 12,900 years ago was a period of intense cold and aridity that put pressure on humans to intensify their foraging strategies but did not favour agriculture. By the beginning of the
Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
11,700 years ago, a warmer climate and increasing human populations led to small-scale animal and plant domestication and an increased supply of food. The appearance of the
domestic dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers ...
in the archaeological record, at least 15,000 years ago, was followed by domestication of livestock and of crops such as
wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...
and
barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...
, the invention of agriculture, and the transition of humans from foraging to farming in different places and times across the planet. For instance, small-scale trial cultivation of cereals began some 28,000 years ago at the Ohalo II site in Israel. In the
Fertile Crescent The Fertile Crescent () is a crescent-shaped region in the Middle East, spanning modern-day Iraq, Israel, Jordan, Lebanon, Palestine, and Syria, together with northern Kuwait, south-eastern Turkey, and western Iran. Some authors also include ...
11,000–10,000 years ago, zooarchaeology indicates that goats, pigs, sheep, and taurine cattle were the first livestock to be domesticated. Two thousand years later, humped zebu cattle were domesticated in what is today Baluchistan in Pakistan. In
East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...
8,000 years ago, pigs were domesticated from wild boar genetically different from those found in the Fertile Crescent. The cat was domesticated in the Fertile Crescent, perhaps 10,000 years ago, from African wildcats, possibly to control
rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
s that were damaging stored food. File:Centres of origin and spread of agriculture labelled.svg, Centres of origin and spread of
agriculture Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
in the Neolithic Revolution as understood in 2003 File:Domestication Timeline.jpg, Rough timelines of domestication for 11 animal species


Animals


Desirable traits

The domestication of vertebrate animals is the relationship between non-human vertebrates and humans who have an influence on their care and reproduction. In his 1868 book ''
The Variation of Animals and Plants Under Domestication ''The Variation of Animals and Plants Under Domestication'' is a book by Charles Darwin that was first published in January 1868. A large proportion of the book contains detailed information on the domestication of animals and plants but it al ...
'',
Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...
recognized the small number of traits that made domestic species different from their wild ancestors. He was also the first to recognize the difference between conscious selective breeding in which humans directly select for desirable traits and unconscious selection, in which traits evolve as a by-product of
natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...
or from selection on other traits. There is a difference between domestic and wild populations; some of these differences constitute the domestication syndrome, traits presumed essential in the early stages of domestication, while others represent later improvement traits. Domesticated mammals in particular tend to be smaller and less aggressive than their wild counterparts; other common traits are floppy ears, a smaller brain, and a shorter muzzle. Domestication traits are generally fixed within all domesticates, and were selected during the initial episode of domestication of that animal or plant, whereas improvement traits are present only in a proportion of domesticates, though they may be fixed in individual breeds or regional populations. Certain animal species, and certain individuals within those species, make better candidates for domestication because of their behavioral characteristics: # The size and organization of their social structure # The availability and the degree of selectivity in their choice of mates # The ease and speed with which the parents bond with their young, and the maturity and mobility of the young at birth # The degree of flexibility in diet and habitat tolerance # Responses to humans and new environments, including reduced flight response and reactivity to external stimuli.


Mammals

The beginnings of mammal domestication involved a protracted coevolutionary process with multiple stages along different pathways. There are three proposed major pathways that most mammal domesticates followed into domestication: # commensals, adapted to a human niche (e.g., dogs,
cats The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...
, possibly
pigs The pig (''Sus domesticus''), also called swine (: swine) or hog, is an omnivorous, domesticated, even-toed, hoofed mammal. It is named the domestic pig when distinguishing it from other members of the genus '' Sus''. Some authorities cons ...
) # prey animals sought for food (e.g., sheep, goats, cattle, water buffalo, yak, pig, reindeer,
llama The llama (; or ) (''Lama glama'') is a domesticated South American camelid, widely used as a List of meat animals, meat and pack animal by Inca empire, Andean cultures since the pre-Columbian era. Llamas are social animals and live with ...
and alpaca) # animals targeted for draft and riding (e.g.,
horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...
,
donkey The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...
, camel). Humans did not intend to domesticate mammals from either the commensal or prey pathways, or at least they did not envision a domesticated animal would result from it. In both of those cases, humans became entangled with these species as the relationship between them intensified, and humans' role in their survival and reproduction gradually led to formalized
animal husbandry Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, animal fiber, fibre, milk, or other products. It includes day-to-day care, management, production, nutrition, selective breeding, and the raising ...
. Although the directed pathway for draft and riding animals proceeded from capture to taming, the other two pathways are not as goal-oriented, and archaeological records suggest that they took place over much longer time frames. Unlike other domestic species selected primarily for production-related traits, dogs were initially selected for their behaviors. The dog was domesticated long before other animals, becoming established across
Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
before the end of the
Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division ...
era, well before
agriculture Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
. The archaeological and genetic data suggest that long-term bidirectional
gene flow In population genetics, gene flow (also known as migration and allele flow) is the transfer of genetic variation, genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent ...
between wild and domestic stocks – such as in
donkey The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...
s,
horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...
s, New and Old World camelids, goats, sheep, and pigs – was common. Human selection for domestic traits likely counteracted the homogenizing effect of gene flow from wild boars into pigs, and created domestication islands in the genome. The same process may apply to other domesticated animals. The 2023 parasite-mediated domestication hypothesis suggests that endoparasites such as helminths and protozoa could have mediated the domestication of mammals. Domestication involves taming, which has an endocrine component; and parasites can modify endocrine activity and microRNAs. Genes for resistance to parasites might be linked to those for the domestication syndrome; it is predicted that domestic animals are less resistant to parasites than their wild relatives.


Birds

Domesticated birds principally mean
poultry Poultry () are domesticated birds kept by humans for the purpose of harvesting animal products such as meat, Eggs as food, eggs or feathers. The practice of animal husbandry, raising poultry is known as poultry farming. These birds are most typ ...
, raised for meat and eggs: some Galliformes (
chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...
,
turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
, guineafowl) and Anseriformes (waterfowl: ducks, geese, and
swan Swans are birds of the genus ''Cygnus'' within the family Anatidae. The swans' closest relatives include the goose, geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe (biology) ...
s). Also widely domesticated are cagebirds such as songbirds and parrots; these are kept both for pleasure and for use in research. The domestic pigeon has been used both for food and as a means of communication between far-flung places through the exploitation of the pigeon's homing instinct; research suggests it was domesticated as early as 10,000 years ago. Chicken fossils in China have been dated to 7,400 years ago. The chicken's wild ancestor is '' Gallus gallus'', the red junglefowl of Southeast Asia. The species appears to have been kept initially for cockfighting rather than for food.


Invertebrates

Two
insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
s, the silkworm and the
western honey bee The western honey bee or European honey bee (''Apis mellifera'') is the most common of the 7–12 species of honey bees worldwide. The genus name ''Apis'' is Latin for 'bee', and ''mellifera'' is the Latin for 'honey-bearing' or 'honey-carrying', ...
, have been domesticated for over 5,000 years, often for commercial use. The silkworm is raised for the silk threads wound around its pupal cocoon; the western honey bee, for
honey Honey is a sweet and viscous substance made by several species of bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the sugary secretions of pl ...
, and, from the 20th century, for pollination of crops. Several other invertebrates have been domesticated, both terrestrial and aquatic, including some such as ''
Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...
'' fruit flies and the freshwater cnidarian '' Hydra'' for research into genetics and physiology. Few have a long history of domestication. Most are used for food or other products such as shellac and
cochineal The cochineal ( , ; ''Dactylopius coccus'') is a scale insect in the suborder Sternorrhyncha, from which the natural dye carmine is derived. A primarily sessility (motility), sessile parasitism, parasite native to tropical and subtropical Sout ...
. The
phyla Phyla, the plural of ''phylum'', may refer to: * Phylum, a biological taxon between Kingdom and Class * by analogy, in linguistics, a large division of possibly related languages, or a major language family which is not subordinate to another Phy ...
involved are
Cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...
, Platyhelminthes (for biological pest control),
Annelida The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to variou ...
,
Mollusca Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
, Arthropoda (marine crustaceans as well as insects and spiders), and
Echinodermata An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, ...
. While many marine mollusks are used for food, only a few have been domesticated, including
squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...
, cuttlefish and octopus, all used in research on behaviour and
neurology Neurology (from , "string, nerve" and the suffix wikt:-logia, -logia, "study of") is the branch of specialty (medicine) , medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous syst ...
. Terrestrial snails in the genera '' Helix'' are raised for food. Several parasitic or parasitoidal insects, including the fly '' Eucelatoria'', the beetle '' Chrysolina'', and the wasp '' Aphytis'' are raised for biological control. Conscious or unconscious artificial selection has many effects on species under domestication; variability can readily be lost by inbreeding, selection against undesired traits, or genetic drift, while in ''Drosophila'', variability in eclosion time (when adults emerge) has increased. File:Cueva arana.svg, A honey hunter in a cave painting at Cuevas de la Araña, Spain, c. 8,000–6,000 BC File:Sericuturist.jpg, Sericulturalists preparing silkworms for spinning of the
silk Silk is a natural fiber, natural protein fiber, some forms of which can be weaving, woven into textiles. The protein fiber of silk is composed mainly of fibroin and is most commonly produced by certain insect larvae to form cocoon (silk), c ...
File:02-Indian-Insect-Life - Harold Maxwell-Lefroy - Kerria-Lacca.jpg, The lac bug ''
Kerria lacca ''Kerria lacca'' is a species of insect in the family Kerriidae, the lac insects. These are in the superfamily scale insect, Coccoidea, the scale insects. This species is perhaps the most commercially important lac insect, being a main source of ...
'' has been kept for shellac resin. File:Snails for Sale - Djermaa el-Fna (Central Square) - Medina (Old City) - Marrakesh - Morocco.jpg, Snails being sold as food


Plants

Humans foraged for wild cereals, seeds, and nuts thousands of years before they were domesticated; wild wheat and barley, for example, were gathered in the Levant at least 23,000 years ago.
Neolithic The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revo ...
societies in West Asia first began to cultivate and then domesticate some of these plants around 13,000 to 11,000 years ago. The founder crops of the West Asian Neolithic included cereals ( emmer, einkorn wheat,
barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...
), pulses ( lentil, pea, chickpea, bitter vetch), and
flax Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. In 2022, France produced 75% of t ...
. Other plants were independently domesticated in 13 centers of origin (subdivided into 24 areas) of the Americas, Africa, and Asia (the Middle East, South Asia, the Far East, and New Guinea and Wallacea); in some thirteen of these regions people began to cultivate grasses and grains. Rice was first cultivated in East Asia.
Sorghum ''Sorghum bicolor'', commonly called sorghum () and also known as great millet, broomcorn, guinea corn, durra, imphee, jowar, or milo, is a species in the Poaceae, grass genus ''Sorghum (genus), Sorghum'' cultivated for its grain. The grain i ...
was widely cultivated in sub-Saharan Africa, while peanuts, squash, cotton,
maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...
, potatoes, and
cassava ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...
were domesticated in the Americas. Continued domestication was gradual and geographically diffuse – happening in many small steps and spread over a wide area – on the evidence of both archaeology and genetics. It was a process of intermittent trial and error and often resulted in diverging traits and characteristics. Whereas domestication of animals impacted most on the genes that controlled behavior, that of plants impacted most on the genes that controlled morphology (seed size, plant architecture, dispersal mechanisms) and physiology (timing of germination or ripening), as in the domestication of wheat. Wild wheat shatters and falls to the ground to reseed itself when ripe, but domesticated wheat stays on the stem for easier harvesting. This change was possible because of a random mutation in the wild populations at the beginning of wheat's cultivation. Wheat with this mutation was harvested more frequently and became the seed for the next crop. Therefore, without realizing it, early farmers selected for this mutation. The result is domesticated wheat, which relies on farmers for its reproduction and dissemination. File:Maler der Grabkammer des Menna 012.jpg, Farmers with wheat and cattle –
Ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...
ian art 3,400 years ago File:Harold f Weston - Iran11.jpg, Wild
wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...
ears shatter when ripe, but domesticated wheat has to be threshed and winnowed (as shown) to release and separate the grain. Photograph by Harold Weston, Iran, 1920s


Differences from wild plants

Domesticated plants differ from their wild relatives in many ways, including * lack of shattering such as of cereal ears (ripe heads), loss of fruit abscission * less efficient breeding system (e.g. without normal pollinating organs, making human intervention a requirement), larger seeds with lower success in the wild, or even sterility (e.g. seedless fruits) and therefore only vegetative reproduction * better palatability (e.g. higher sugar content, reduced bitterness), better smell, and lower toxicity * edible part larger, e.g. cereal grains or fruits * edible part more easily separated from non-edible part * increased number of fruits or grains * altered color, taste, and texture * daylength independence * determinate growth * reduced or no vernalization * less seed dormancy. Plant defenses against herbivory, such as thorns, spines, and prickles, poison, protective coverings, and sturdiness may have been reduced in domesticated plants. This would make them more likely to be eaten by herbivores unless protected by humans, but there is only weak support for most of this. Farmers did select for reduced bitterness and lower toxicity and for food quality, which likely increased crop palatability to herbivores as to humans. However, a survey of 29 plant domestications found that crops were as well-defended against two major insect pests ( beet armyworm and green peach aphid) both chemically (e.g. with bitter substances) and morphologically (e.g. with toughness) as their wild ancestors.


Changes to plant genome

During domestication, crop species undergo intense artificial selection that alters their genomes, establishing core traits that define them as domesticated, such as increased grain size. Comparison of the coding DNA of
chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
8 in rice between fragrant and non-fragrant varieties showed that aromatic and fragrant rice, including basmati and
jasmine Jasmine (botanical name: ''Jasminum'', pronounced ) is a genus of shrubs and vines in the olive family of Oleaceae. It contains around 200 species native to tropical and warm temperate regions of Eurasia, Africa, and Oceania. Jasmines are wid ...
, is derived from an ancestral rice domesticate that suffered a deletion in
exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence ...
7 which altered the coding for betaine aldehyde dehydrogenase (BADH2). Comparison of the potato genome with that of other plants located genes for resistance to potato blight caused by '' Phytophthora infestans''. In
coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family (biology), family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, ...
, genomic analysis of 10 microsatellite loci (of noncoding DNA) found two episodes of domestication based on differences between individuals in the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
and those in the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
. The coconut experienced a
founder effect In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, us ...
, where a small number of individuals with low diversity founded the modern population, permanently losing much of the genetic variation of the wild population. Population bottlenecks which reduced variation throughout the genome at some later date after domestication are evident in crops such as
pearl millet Pearl millet (''Cenchrus americanus'', commonly known as the synonym ''Pennisetum glaucum'') is the most widely grown type of millet. It has been grown in Africa and the Indian subcontinent since prehistoric times. The center of diversity, and ...
,
cotton Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...
,
common bean ''Phaseolus vulgaris'', the common bean,, is a herbaceous annual plant grown worldwide for its edible dry seeds or green bean, green, unripe pods. Its leaf is also occasionally used as a Leaf vegetable, vegetable and the straw as fodder. Its Pla ...
and lima bean. In wheat, domestication involved repeated hybridization and polyploidy. These steps are large and essentially instantaneous changes to the genome and the epigenome, enabling a rapid evolutionary response to artificial selection. Polyploidy increases the number of chromosomes, bringing new combinations of genes and alleles, which in turn enable further changes such as by chromosomal crossover.


Impact on plant microbiome

The microbiome, the collection of
microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...
s inhabiting the surface and internal tissue of plants, is affected by domestication. This includes changes in microbial species composition and diversity. Plant lineage, including speciation, domestication, and breeding, have shaped plant endophytes ( phylosymbiosis) in similar patterns as plant genes.


Fungi

Several species of
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
have been domesticated for use directly as food, or in fermentation to produce foods and drugs. The cultivated mushroom '' Agaricus bisporus'' is widely grown for food. The yeast ''
Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungal microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have be ...
'' have been used for thousands of years to ferment
beer Beer is an alcoholic beverage produced by the brewing and fermentation of starches from cereal grain—most commonly malted barley, although wheat, maize (corn), rice, and oats are also used. The grain is mashed to convert starch in the ...
and
wine Wine is an alcoholic drink made from Fermentation in winemaking, fermented fruit. Yeast in winemaking, Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made f ...
, and to leaven
bread Bread is a baked food product made from water, flour, and often yeast. It is a staple food across the world, particularly in Europe and the Middle East. Throughout recorded history and around the world, it has been an important part of many cu ...
. Mould fungi including ''
Penicillium ''Penicillium'' () is a genus of Ascomycota, ascomycetous fungus, fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production. Some members of th ...
'' are used to mature
cheese Cheese is a type of dairy product produced in a range of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk (usually the milk of cows, buffalo, goats or sheep). During prod ...
s and other dairy products, as well as to make drugs such as
antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...
.


Effects


On domestic animals

Selection of animals for visible traits may have undesired consequences for the genetics of domestic animals. A side effect of domestication has been zoonotic diseases. For example, cattle have given humanity various viral poxes,
measles Measles (probably from Middle Dutch or Middle High German ''masel(e)'', meaning "blemish, blood blister") is a highly contagious, Vaccine-preventable diseases, vaccine-preventable infectious disease caused by Measles morbillivirus, measles v ...
, and
tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...
; pigs and ducks have contributed influenza; and horses have brought the
rhinovirus The rhinovirus (from the "nose", , romanized: "of the nose", and the ) is a Positive-sense single stranded RNA virus, positive-sense, single-stranded RNA virus belonging to the genus ''Enterovirus'' in the family ''Picornaviridae''. Rhinoviru ...
es. Many
parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...
s, too, have their origins in domestic animals. Alongside these, the advent of domestication resulted in denser human populations, which provided ripe conditions for pathogens to reproduce, mutate, spread, and eventually find a new host in humans.


On society

Scholars have expressed widely differing viewpoints on domestication's effects on society. Anarcho-primitivism critiques domestication as destroying the supposed primitive state of harmony with nature in hunter-gatherer societies, and replacing it, possibly violently or by enslavement, with a social
hierarchy A hierarchy (from Ancient Greek, Greek: , from , 'president of sacred rites') is an arrangement of items (objects, names, values, categories, etc.) that are represented as being "above", "below", or "at the same level as" one another. Hierarchy ...
as property and power emerged. The dialectal naturalist Murray Bookchin has argued that domestication of animals, in turn, meant the domestication of humanity, both parties being unavoidably altered by their relationship with each other. The sociologist David Nibert asserts that the domestication of animals involved violence against animals and damage to the environment. This, in turn, he argues, corrupted human ethics and paved the way for "conquest, extermination, displacement, repression, coerced and enslaved servitude, gender subordination and sexual exploitation, and hunger."


On diversity

Domesticated ecosystems provide food, reduce predator and natural dangers, and promote commerce, but their creation has resulted in habitat alteration or loss, and multiple extinctions commencing in the Late Pleistocene. Domestication reduces
genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. It ranges widely, from the number of species to differences within species, and can be correlated to the span of survival for a species. It is d ...
of the domesticated population, especially of alleles of genes targeted by selection. One reason is a population bottleneck created by artificially selecting the most desirable individuals to breed from. Most of the domesticated strain is then born from just a few ancestors, creating a situation similar to the
founder effect In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, us ...
. Domesticated populations such as of dogs, rice, sunflowers, maize, and horses have an increased mutation load, as expected in a population bottleneck where genetic drift is enhanced by the small population size. Mutations can also be fixed in a population by a selective sweep. Mutational load can be increased by reduced selective pressure against moderately harmful traits when reproductive fitness is controlled by human management. However, there is evidence against a bottleneck in crops, such as barley, maize, and sorghum, where genetic diversity slowly declined rather than showing a rapid initial fall at the point of domestication. Further, the genetic diversity of these crops was regularly replenished from the natural population. Similar evidence exists for horses, pigs, cows, and goats.


Domestication by insects

At least three groups of insects, namely ambrosia beetles, leafcutter ants, and fungus-growing termites, have domesticated species of
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
.


Ambrosia beetles

Ambrosia beetles in the weevil subfamilies Scolytinae and Platypodinae excavate tunnels in dead or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont. The fungus penetrates the plant's
xylem Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts o ...
tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which is an attractant for ambrosia beetles and likely prevents the growth of antagonistic pathogens and selects for other beneficial symbionts. Ambrosia beetles mainly colonise wood of recently dead trees.


Leafcutter ants

The leafcutter ants are any of some 47 species of leaf-chewing ants in the genera '' Acromyrmex'' and '' Atta''. The ants carry the discs of leaves that they have cut back to their nest, where they feed the leaf material to the fungi that they tend. Some of these fungi are not fully domesticated: the fungi farmed by '' Mycocepurus smithii'' constantly produce spores that are not useful to the ants, which eat fungal hyphae instead. The process of domestication by ''Atta'' ants, on the other hand, is complete; it took 30 million years.


Fungus-growing termites

Some 330 fungus-growing termite species of the subfamily Macrotermitinae cultivate '' Termitomyces'' fungi to eat; domestication occurred exactly once, 25–40 mya. The fungi, described by Roger Heim in 1942, grow on 'combs' formed from the termites' excreta, dominated by tough woody fragments. The termites and the fungi are both obligate symbionts in the relationship. File:Xylosandrus crassiusculus galleryR.jpg, Gallery of the ambrosia beetle '' Xylosandrus crassiusculus'' split open, with pupae and black fungus. The fungus decomposes materials in the wood, providing food for the beetles. File:leaf cutter ants arp.jpg, Leafcutter ants '' Atta cephalotes'' carrying discs of leaf material back to their nest to feed to their domesticated fungus Ancistrotermes latinotus.jpg, Inside the nest of the fungus-cultivating termite '' Ancistrotermes'' File:Termitomyces heimii.jpg, '' Termitomyces heimii'' growing on 'comb' inside a termite mound File:Termitomyces reticulatus 37340.jpg, '' Termitomyces'' fungi are mutually dependent on Macrotermitinae termites for their survival.


See also

* Anthrozoology * ''De novo'' domestication * Domestication theory * Experimental evolution * Genetic erosion * Self-domestication * Timeline of agriculture and food technology


References


Sources

* * * * * *


External links


Crop Wild Relative Inventory and Gap Analysis
reliable information source on where and what to conserve ex-situ for crop gene pools of global importance


The Initial Domestication of ''Cucurbita pepo'' in the Americas 10,000 Years Ago

Cattle domestication diagram

Major topic 'domestication': free full-text articles (more than 100 plus reviews) in National Library of Medicine
{{Authority control History of agriculture