71-633: See text . Semecarpus is a genus of plants in the family Anacardiaceae . It includes 87 species native to the Indian subcontinent, Indochina, Malesia, Taiwan, Papuasia, Queensland, and the South Pacific. The genus Semecarpus was erected by Carl Linnaeus the Younger in 1782 in Supplementum Plantarum . In the same work, he described Semecarpus anacardium . The gender of the genus name has been
142-420: 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
213-854: A few have been domesticated, including squid , cuttlefish and octopus , all used in research on behaviour and neurology . 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. Humans foraged for wild cereals, seeds, and nuts thousands of years before they were domesticated; wild wheat and barley, for example, were gathered in
284-480: 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. Two insects ,
355-468: 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
426-779: 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 termites , ambrosia beetles , and leafcutter ants have domesticated some species of fungi , and notes further that other groups such as weeds and commensals have wrongly been called domesticated. Starting from Zeder's definition, Purugganan proposes
497-545: A protective response. The first such plant receptors were identified in rice and in Arabidopsis thaliana . Plants have some of the largest genomes of all organisms. The largest plant genome (in terms of gene number) is that of wheat ( Triticum aestivum ), predicted to encode ≈94,000 genes and thus almost 5 times as many as the human genome . The first plant genome sequenced was that of Arabidopsis thaliana which encodes about 25,500 genes. In terms of sheer DNA sequence,
568-425: A protracted coevolutionary process with multiple stages along different pathways. There are three proposed major pathways that most mammal domesticates followed into domestication: 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
639-420: A range of physical and biotic stresses which cause DNA damage , but they can tolerate and repair much of this damage. Plants reproduce to generate offspring, whether sexually , involving gametes , or asexually , involving ordinary growth. Many plants use both mechanisms. When reproducing sexually, plants have complex lifecycles involving alternation of generations . One generation, the sporophyte , which
710-575: 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. At least three groups of insects, namely ambrosia beetles, leafcutter ants, and fungus-growing termites, have domesticated species of fungi . 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
781-402: A suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont . The fungus penetrates the plant's xylem 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
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#1733085453771852-468: A working animal. Among invertebrates , the silkworm and the western honey bee were domesticated over 5,000 years ago for silk and honey , respectively. The domestication of plants began around 13,000–11,000 years ago with cereals such as wheat and barley in the Middle East , alongside crops such as lentil , pea , chickpea , and flax . Beginning around 10,000 years ago, Indigenous peoples in
923-404: Is diploid (with 2 sets of chromosomes ), gives rise to the next generation, the gametophyte , which is haploid (with one set of chromosomes). Some plants also reproduce asexually via spores . In some non-flowering plants such as mosses, the sexual gametophyte forms most of the visible plant. In seed plants (gymnosperms and flowering plants), the sporophyte forms most of the visible plant, and
994-525: 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
1065-547: Is a similar process. Structures such as runners enable plants to grow to cover an area, forming a clone . Many plants grow food storage structures such as tubers or bulbs which may each develop into a new plant. Some non-flowering plants, such as many liverworts, mosses and some clubmosses, along with a few flowering plants, grow small clumps of cells called gemmae which can detach and grow. Plants use pattern-recognition receptors to recognize pathogens such as bacteria that cause plant diseases. This recognition triggers
1136-405: 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. 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
1207-432: Is domesticated wheat, which relies on farmers for its reproduction and dissemination. Domesticated plants differ from their wild relatives in many ways, including 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
1278-496: Is known as botany , a branch of biology . All living things were traditionally placed into one of two groups, plants and animals . This classification dates from Aristotle (384–322 BC), who distinguished different levels of beings in his biology , based on whether living things had a "sensitive soul" or like plants only a "vegetative soul". Theophrastus , Aristotle's student, continued his work in plant taxonomy and classification. Much later, Linnaeus (1707–1778) created
1349-669: 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. 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
1420-668: 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. The domestication of animals and plants
1491-712: Is today Baluchistan in Pakistan. In East Asia 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 European wildcats , possibly to control rodents that were damaging stored food. 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 , Charles Darwin recognized
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#17330854537711562-636: Is widely grown for food. The yeast Saccharomyces cerevisiae have been used for thousands of years to ferment beer and wine , and to leaven bread . Mould fungi including Penicillium are used to mature cheeses and other dairy products, as well as to make drugs such as antibiotics . 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 , and tuberculosis ; pigs and ducks have contributed influenza ; and horses have brought
1633-595: The Antarctic flora , consisting of algae, mosses, liverworts, lichens, and just two flowering plants, have adapted to the prevailing conditions on that southern continent. Plants are often the dominant physical and structural component of the habitats where they occur. Many of the Earth's biomes are named for the type of vegetation because plants are the dominant organisms in those biomes, such as grassland , savanna , and tropical rainforest . Domesticated Domestication
1704-679: The Cretaceous so rapid that Darwin called it an " abominable mystery ". Conifers diversified from the Late Triassic onwards, and became a dominant part of floras in the Jurassic . In 2019, a phylogeny based on genomes and transcriptomes from 1,153 plant species was proposed. The placing of algal groups is supported by phylogenies based on genomes from the Mesostigmatophyceae and Chlorokybophyceae that have since been sequenced. Both
1775-705: The Indian Ocean and those in the Pacific Ocean . The coconut experienced a founder effect , 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 , cotton , common bean and lima bean . In wheat, domestication involved repeated hybridization and polyploidy . These steps are large and essentially instantaneous changes to
1846-616: The Levant at least 23,000 years ago. Neolithic 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 ), pulses ( lentil , pea , chickpea , bitter vetch ), and flax . Other plants were independently domesticated in 13 centers of origin (subdivided into 24 areas) of
1917-457: The carpels or ovaries , which develop into fruits that contain seeds . Fruits may be dispersed whole, or they may split open and the seeds dispersed individually. Plants reproduce asexually by growing any of a wide variety of structures capable of growing into new plants. At the simplest, plants such as mosses or liverworts may be broken into pieces, each of which may regrow into whole plants. The propagation of flowering plants by cuttings
1988-619: The coding DNA of chromosome 8 in rice between fragrant and non-fragrant varieties showed that aromatic and fragrant rice, including basmati and jasmine , is derived from an ancestral rice domesticate that suffered a deletion in exon 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 , genomic analysis of 10 microsatellite loci (of noncoding DNA ) found two episodes of domestication based on differences between individuals in
2059-470: 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
2130-417: 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
2201-437: The rhinoviruses . Many parasites , 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. Scholars have expressed widely differing viewpoints on domestication's effects on society. Anarcho-primitivism critiques domestication as destroying
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2272-600: 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 goats , sheep , and cows , were domesticated around 11,000 years ago. Among birds, the chicken 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
2343-436: The silkworm and the western honey bee , 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 , 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 fruit flies and
2414-1003: The "chlorophyte algae" and the "streptophyte algae" are treated as paraphyletic (vertical bars beside phylogenetic tree diagram) in this analysis, as the land plants arose from within those groups. The classification of Bryophyta is supported both by Puttick et al. 2018, and by phylogenies involving the hornwort genomes that have also since been sequenced. Rhodophyta [REDACTED] Glaucophyta [REDACTED] Chlorophyta [REDACTED] Prasinococcales Mesostigmatophyceae Chlorokybophyceae Spirotaenia [REDACTED] Klebsormidiales [REDACTED] Chara [REDACTED] Coleochaetales [REDACTED] Hornworts [REDACTED] Liverworts [REDACTED] Mosses [REDACTED] Lycophytes [REDACTED] [REDACTED] Gymnosperms [REDACTED] Angiosperms [REDACTED] Plant cells have distinctive features that other eukaryotic cells (such as those of animals) lack. These include
2485-550: The Americas began to cultivate peanuts , squash , maize , potatoes , cotton , and cassava . Rice was first domesticated in China some about 9,000 years ago. In Africa, crops such as sorghum 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
2556-524: 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 was widely cultivated in sub-Saharan Africa, while peanuts, squash, cotton, maize , potatoes , and cassava were domesticated in the Americas. Continued domestication
2627-668: The Greek masculine ‑carpos or ‑carpus are masculine. As of June 2022, the International Plant Names Index and Plants of the World Online used masculine endings, such as Semecarpus heterophyllus and Semecarpus longifolius , while the Global Biodiversity Information Facility had mixed endings, such as Semecarpus heterophylla and Semecarpus longifolius . As of June 2022, Plants of
2698-587: The Late Pleistocene. Domestication reduces genetic diversity 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 . Domesticated populations such as of dogs, rice, sunflowers, maize, and horses have an increased mutation load , as expected in
2769-456: The World Online accepted the following species: Plant See text Plants are the eukaryotes that form the kingdom Plantae ; they are predominantly photosynthetic . This means that they obtain their energy from sunlight , using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll . Exceptions are parasitic plants that have lost
2840-472: The algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants ( hornworts , liverworts , mosses , lycophytes , ferns , conifers and other gymnosperms , and flowering plants ). A definition based on genomes includes the Viridiplantae, along with the red algae and the glaucophytes , in
2911-801: The amount of cytoplasm stays the same. Most plants are multicellular . Plant cells differentiate into multiple cell types, forming tissues such as the vascular tissue with specialized xylem and phloem of leaf veins and stems , and organs with different physiological functions such as roots to absorb water and minerals, stems for support and to transport water and synthesized molecules, leaves for photosynthesis, and flowers for reproduction. Plants photosynthesize , manufacturing food molecules ( sugars ) using energy obtained from light . Plant cells contain chlorophylls inside their chloroplasts, which are green pigments that are used to capture light energy. The end-to-end chemical equation for photosynthesis is: This causes plants to release oxygen into
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2982-431: The atmosphere. Green plants provide a substantial proportion of the world's molecular oxygen, alongside the contributions from photosynthetic algae and cyanobacteria. Plants that have secondarily adopted a parasitic lifestyle may lose the genes involved in photosynthesis and the production of chlorophyll. Growth is determined by the interaction of a plant's genome with its physical and biotic environment. Factors of
3053-461: The basis of the modern system of scientific classification , but retained the animal and plant kingdoms , naming the plant kingdom the Vegetabilia. When the name Plantae or plant is applied to a specific group of organisms or taxa , it usually refers to one of four concepts. From least to most inclusive, these four groupings are: There are about 382,000 accepted species of plants, of which
3124-453: The beginning of the Holocene 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 in the archaeological record, at least 15,000 years ago, was followed by domestication of livestock and of crops such as wheat and barley , the invention of agriculture , and
3195-553: The case of the termites, the relationship is a fully obligate symbiosis on both sides. Domestication (not to be confused with the taming of an individual animal ), is from the Latin domesticus , '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
3266-728: The clade Archaeplastida . There are about 380,000 known species of plants, of which the majority, some 260,000, produce seeds . They range in size from single cells to the tallest trees . Green plants provide a substantial proportion of the world's molecular oxygen; the sugars they create supply the energy for most of Earth's ecosystems and other organisms , including animals, either eat plants directly or rely on organisms which do so. Grain , fruit , and vegetables are basic human foods and have been domesticated for millennia. People use plants for many purposes , such as building materials , ornaments, writing materials , and, in great variety, for medicines . The scientific study of plants
3337-483: The development of forests in swampy environments dominated by clubmosses and horsetails, including some as large as trees, and the appearance of early gymnosperms , the first seed plants . The Permo-Triassic extinction event radically changed the structures of communities. This may have set the scene for the evolution of flowering plants in the Triassic (~ 200 million years ago ), with an adaptive radiation in
3408-509: 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." 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
3479-515: The domestication syndrome; it is predicted that domestic animals are less resistant to parasites than their wild relatives. Domesticated birds principally mean poultry , raised for meat and eggs: some Galliformes ( chicken , turkey , guineafowl ) and Anseriformes (waterfowl: ducks , geese , and swans ). 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
3550-447: 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 phyla involved are Cnidaria , Platyhelminthes (for biological pest control ), Annelida , Mollusca , Arthropoda (marine crustaceans as well as insects and spiders), and Echinodermata . While many marine mollusks are used for food, only
3621-409: The gametophyte is very small. Flowering plants reproduce sexually using flowers, which contain male and female parts: these may be within the same ( hermaphrodite ) flower, on different flowers on the same plant , or on different plants . The stamens create pollen , which produces male gametes that enter the ovule to fertilize the egg cell of the female gametophyte. Fertilization takes place within
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#17330854537713692-450: The genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular , except for some green algae. Historically, as in Aristotle's biology , the plant kingdom encompassed all living things that were not animals , and included algae and fungi . Definitions have narrowed since then; current definitions exclude the fungi and some of
3763-810: 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 . The microbiome , the collection of microorganisms 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. Several species of fungi have been domesticated for use directly as food, or in fermentation to produce foods and drugs. The cultivated mushroom Agaricus bisporus
3834-575: The great majority, some 283,000, produce seeds . The table below shows some species count estimates of different green plant (Viridiplantae) divisions . About 85–90% of all plants are flowering plants. Several projects are currently attempting to collect records on all plant species in online databases, e.g. the World Flora Online . Plants range in scale from single-celled organisms such as desmids (from 10 micrometres (μm) across) and picozoa (less than 3 μm across), to
3905-532: 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
3976-426: 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 beginnings of mammal domestication involved
4047-517: The land 1,200 million years ago , but it was not until the Ordovician , around 450 million years ago , that the first land plants appeared, with a level of organisation like that of bryophytes. However, fossils of organisms with a flattened thallus in Precambrian rocks suggest that multicellular freshwater eukaryotes existed over 1000 mya. Primitive land plants began to diversify in
4118-412: The large water-filled central vacuole , chloroplasts , and the strong flexible cell wall , which is outside the cell membrane . Chloroplasts are derived from what was once a symbiosis of a non-photosynthetic cell and photosynthetic cyanobacteria . The cell wall, made mostly of cellulose , allows plant cells to swell up with water without bursting. The vacuole allows the cell to change in size while
4189-507: The largest trees ( megaflora ) such as the conifer Sequoia sempervirens (up to 120 metres (380 ft) tall) and the angiosperm Eucalyptus regnans (up to 100 m (325 ft) tall). The naming of plants is governed by the International Code of Nomenclature for algae, fungi, and plants and the International Code of Nomenclature for Cultivated Plants . The ancestors of land plants evolved in water. An algal scum formed on
4260-656: The late Silurian , around 420 million years ago . Bryophytes, club mosses, and ferns then appear in the fossil record. Early plant anatomy is preserved in cellular detail in an early Devonian fossil assemblage from the Rhynie chert . These early plants were preserved by being petrified in chert formed in silica-rich volcanic hot springs. By the end of the Devonian, most of the basic features of plants today were present, including roots, leaves and secondary wood in trees such as Archaeopteris . The Carboniferous period saw
4331-580: 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. 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
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#17330854537714402-501: The physical or abiotic environment include temperature , water , light, carbon dioxide , and nutrients in the soil. Biotic factors that affect plant growth include crowding, grazing, beneficial symbiotic bacteria and fungi, and attacks by insects or plant diseases . Frost and dehydration can damage or kill plants. Some plants have antifreeze proteins , heat-shock proteins and sugars in their cytoplasm that enable them to tolerate these stresses . Plants are continuously exposed to
4473-514: The relationship between them intensified, and humans' role in their survival and reproduction gradually led to formalized animal husbandry . 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
4544-459: 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 or from selection on other traits. There is a difference between domestic and wild populations; some of these differences constitute
4615-465: The smallest published genome is that of the carnivorous bladderwort ( Utricularia gibba) at 82 Mb (although it still encodes 28,500 genes) while the largest, from the Norway spruce ( Picea abies ), extends over 19.6 Gb (encoding about 28,300 genes). Plants are distributed almost worldwide. While they inhabit several biomes which can be divided into a multitude of ecoregions , only the hardy plants of
4686-475: The subject of some confusion. Early authors treated it as feminine. As one example, in 1850, Carl Ludwig Blume described a number of species of Semecarpus , such as Semecarpus heterophylla and Semecarpus longifolia , using feminine endings for the specific epithet. However, Example 3 of Article 62 of the International Code of Nomenclature for algae, fungi, and plants states that all compounds ending in
4757-451: The supposed primitive state of harmony with nature in hunter-gatherer societies, and replacing it, possibly violently or by enslavement, with a social 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
4828-620: 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 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
4899-492: Was domesticated long before other animals, becoming established across Eurasia before the end of the Late Pleistocene era, well before agriculture . The archaeological and genetic data suggest that long-term bidirectional gene flow between wild and domestic stocks – such as in donkeys , horses , New and Old World camelids, goats, sheep, and pigs – was common. Human selection for domestic traits likely counteracted
4970-532: 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
5041-548: Was triggered by the climatic and environmental changes that occurred after the peak of the Last Glacial Maximum 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
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