Relationship between domestic plants and animals

Domestication (anthropology) - AccessScience from McGraw-Hill Education

relationship between domestic plants and animals

The fundamental distinction of domesticated animals and plants from their wild . Traditionally, the main criteria for judging relationships between domestic or. Links to Primary Literature; Additional Readings Domesticated plants and animals provide humans with a variety of useful products, including food and fibers. Domestication of plants and animals marks a major transition in human or how and when it results in the creation of a domesticated plant or animal. in terms of the relationship between humans and target species that.

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Cattle, at the initial stages of domestication, produced a small amount of milksufficient only to rear their calves. The development of high milk yield in cows with their breeding especially for milk production is a later event in the history of domestication. The first domesticated horses were also used for meat and skin. Later the horse played an enormous role in the waging of war.

Peoples inhabiting the Middle East in the 2nd millennium bce used horses in chariot battles.

relationship between domestic plants and animals

With time the horse began to be used as transportation. In the 1st millennium bce carts appeared, and the horses were harnessed to them; other riding equipment, including the saddle and the bit, seems to have appeared in later centuries. The donkey and the camel were used only for load transport and as means of conveyance; their unpalatability ruled out their use as a preferred food.

The first domesticated hens perhaps were used for sport. Cockfighting was instrumental in bringing about the selection of these birds for larger size. Cocks later acquired religious significance. In Zoroastrianism the cock was associated with protection of good against evil and was a symbol of light. In ancient Greece it was also an object of sacrifice to gods.

relationship between domestic plants and animals

It is probable that egg production of the first domesticated hens was no more than five to ten eggs a year; high egg yield and improved meat qualities of hens developed at later stages of domestication.

Early domestication of the cat was probably the result of the pleasure experienced from keeping this animal. In ancient Egypt the cat was considered a sacred animal. Some animals were domesticated for utilitarian purposes from the very beginning.

Here belongs, first of all, the rabbitwhose real domestication was carried out from the 6th to the 10th century ce by French monks. For the sake of honeythe bee was domesticated at the end of the Neolithic Period. Honey has played an enormous role in human nutrition since ancient times; it ceased being the sole sweetening agent only about years ago.

Bees also provided wax and bee venomwhich was used as medicine. Bees were used also, to a limited extent, in warfarehives being thrown among enemy troops to rout them. To obtain silkthe silkworm was domesticated in China no later than bce, and by bce the technology of silkworm breeding and raising had been thoroughly documented.

relationship between domestic plants and animals

Shepherdy and nomadic animal breedingwhich determined the social and economic organization and the way of life of some peoples to a great extent, appeared at later stages of human development, after the accumulation of a large number of domestic animals.

Rudiments of nomadic animal breeding in Eurasia appeared no earlier than bce, considerably after the domestication of animals took place. The process of domestication in the New World took place somewhat later than in the Old World and independently of the latter, since humans first appeared in the New World only during the end of the Pleistocene Epoch which lasted from 2.

Biological and genetic changes Traditionally, the main criteria for judging relationships between domestic or cultivated organisms and wild ancestors were similarities of structure and function, but cytogenetical examinations, particularly comparisons of chromosomes and chromosome sets, also are adding to the knowledge of the origins of domesticated organisms. With animals, morphological and biochemical i.

During the 11, or 12, years that have passed since the beginning of domestication, the animals and plants that humans have selected as useful to them have undergone profound changes. The consequences of domestication are so great that the differences between breeds of animals or varieties of plants of the same species often exceed those between different species under natural conditions.

The most important consequence of domestication of animals consists of a sharp change in their seasonal biology. Taming is the conditioned behavioral modification of a wild-born animal when its natural avoidance of humans is reduced and it accepts the presence of humans, but domestication is the permanent genetic modification of a bred lineage that leads to an inherited predisposition toward humans. Wild animals can be tame, such as a hand-raised cheetah.

A domestic animal's breeding is controlled by humans and its tameness and tolerance of humans is genetically determined. However, an animal merely bred in captivity is not necessarily domesticated.

Tigers, gorillas, and polar bears breed readily in captivity but are not domesticated. History of agriculture The domestication of animals began with the wolf Canis lupus at least 15, years before present YBPwhich then led to a rapid shift in the evolutionecologyand demography of both humans and numerous species of animals and plants.

Domestication

Various criteria have been established to provide a definition of domestic animals, but all decisions about exactly when an animal can be labelled "domesticated" in the zoological sense are arbitrary, although potentially useful.

However, there are universal features held in common by all domesticated animals.

relationship between domestic plants and animals

Fig 1 [13] [14] [15] Reduced wariness to humans and low reactivity to both humans and other external stimuli are a key pre-adaptation for domestication, and these behaviors are also the primary target of the selective pressures experienced by the animal undergoing domestication. Carnivores feed on flesh, which would require the domesticators to raise additional animals to feed the carnivores and therefore increase the consumption of plants further.

Some large animals require many years before they reach a useful size. This arrangement allows humans to take control of the dominance hierarchy. Brain size and function[ edit ] Reduction in skull size with neoteny - grey wolf and chihuahua skulls The sustained selection for lowered reactivity among mammal domesticates has resulted in profound changes in brain form and function.

The larger the size of the brain to begin with and the greater its degree of folding, the greater the degree of brain-size reduction under domestication. This portion of the brain regulates endocrine function that influences behaviors such as aggression, wariness, and responses to environmentally induced stress, all attributes which are dramatically affected by domestication.

Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits. Certain physiological changes characterize domestic animals of many species. These changes include extensive white markings particularly on the headfloppy ears, and curly tails. These arise even when tameness is the trait under selective pressure.

Domestication of animals

Tameness may be caused by the down regulation of fear and stress responses via reduction of the adrenal glands. The Neural Crest Hypothesis relates adrenal gland function to deficits in neural crest cells during development.

The Single Genetic Regulatory Network Hypothesis claims that genetic changes in upstream regulators affect downstream systems. Although they do not affect the development of the adrenal cortex directly, the neural crest cells may be involved in relevant upstream embryological interactions. They may be forms intermediate between both parents, forms more similar to one parent than the other, or unique forms distinct from both parents. Hybrids can be intentionally bred for specific characteristics or can arise unintentionally as the result of contact with wild individuals.

As such, they experience relaxed artificial selection induced by the captive environment paired with intensified natural selection induced by the wild habitat. The study showed clear differences between the dental phenotypes of wild, captive wild, domestic, and hybrid pig populations, which supported the proposed categories through physical evidence.

The study did not cover feral pig populations but called for further research to be undertaken on them, and on the genetic differences with hybrid pigs. The first group proposed that animal domestication proceeded along a continuum of stages from anthropophily, commensalism, control in the wild, control of captive animals, extensive breeding, intensive breeding, and finally to pets in a slow, gradually intensifying relationship between humans and animals.

Humans did not intend to domesticate animals from, or at least they did not envision a domesticated animal resulting from, either the commensal or prey pathways. In both of these cases, humans became entangled with these species as the relationship between them, and the human role in their survival and reproduction, intensified.

Those animals established a commensal relationship with humans in which the animals benefited but the humans received no harm but little benefit.

Those animals that were most capable of taking advantage of the resources associated with human camps would have been the tamer, less aggressive individuals with shorter fight or flight distances.

From this perspective, animal domestication is a coevolutionary process in which a population responds to selective pressure while adapting to a novel niche that included another species with evolving behaviors. The dog is a classic example of a domestic animal that likely traveled a commensal pathway into domestication.

The dog was the first domesticant [23] [24] and was domesticated and widely established across Eurasia before the end of the Pleistocenewell before cultivation or the domestication of other animals. Though these two populations spend a period of the year in the same place, and though there was evidence of gene flow between them, the difference in prey—habitat specialization has been sufficient to maintain genetic and even coloration divergence. The skull shape, tooth wear, and isotopic signatures suggested these were specialist megafauna hunters and scavengers that became extinct while less specialized wolf ecotypes survived.

Although the chicken was domesticated in South-East Asia, archaeological evidence suggests that it was not kept as a livestock species until BCE in the Levant.