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Interbreeding
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neanderthals
Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an Extinction, extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While the "causes of Neanderthal disappearance about 40,000 years ago remain highly contested," demographic factors such as small population size, inbreeding and genetic drift, are considered probable factors. Other scholars have proposed competitive replacement, assimilation into the modern human genome (bred into extinction), great climate change, climatic change, disease, or a combination of these factors. It is unclear when the line of Neanderthals split from that of Early modern human, modern humans; studies have produced various intervals ranging from 315,000 to more than 800,000 years ago. The date of divergence of Neanderthals from their ancestor ''Homo heidelbergensis, H. heidelbergensis'' is also unclear. The oldest potential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaic Human Admixture With Modern Humans
There is evidence for interbreeding between archaic and modern humans during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins. In Eurasia, interbreeding between Neanderthals and Denisovans with modern humans took place several times. The introgression events into modern humans are estimated to have happened about 47,000–65,000 years ago with Neanderthals and about 44,000–54,000 years ago with Denisovans. Neanderthal-derived DNA has been found in the genomes of most or possibly all contemporary populations, varying noticeably by region. It accounts for 1–4% of modern genomes for people outside Sub-Saharan Africa, although estimates vary, and either none or possibly up to 0.3% — according to recent research — for those in Africa. It is highest in East Asians, intermediate in Europeans, and lower in Southeast Asians. According to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horticulture
Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and non-food crops such as grass and ornamental trees and plants. It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance, and arboriculture, ornamental trees and lawns. The study and practice of horticulture have been traced back thousands of years. Horticulture contributed to the transition from nomadic human communities to sedentary, or semi-sedentary, horticultural communities.von Hagen, V.W. (1957) The Ancient Sun Kingdoms Of The Americas. Ohio: The World Publishing Company Horticulture is divided into several categories which focus on the cultivation and processing of different types of plants and food items for specific purposes. In order to conserve the science of horticultur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundation Stock
Foundation bloodstock or foundation stock refers to animals that are the progenitors, or foundation, of a breed or of a given bloodline within such. Many modern breeds can be traced to specific, named foundation animals, but a group of animals may be referred to collectively as foundation bloodstock when one distinct population (including both landrace breeds or a group of animals linked to a deliberate and specific selective breeding program) provides part of the underlying genetic base for a new distinct population. Terminology The terms for foundation ancestors differ by sex, most commonly "foundation sire" for the father and "foundation dam" for the mother. Depending upon the species in question, more specialized terms may be used, such as ''foundation mare'' for female horses, ''foundation queen'' for female cats, or ''foundation bitch'' for female dogs. The offspring of genetically dissimilar parents or stock, whether of different species or different breeds are technica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossbreed
A crossbreed is an organism with purebred parents of two different breeds, varieties, or populations. ''Crossbreeding'', sometimes called "designer crossbreeding", is the process of breeding such an organism, While crossbreeding is used to maintain health and viability of organisms, irresponsible crossbreeding can also produce organisms of inferior quality or dilute a purebred gene pool to the point of extinction of a given breed of organism. A domestic animal of unknown ancestry, where the breed status of only one parent or grandparent is known, may also be called a crossbreed though the term "mixed breed" is technically more accurate. Outcrossing is a type of crossbreeding used within a purebred breed to increase the genetic diversity within the breed, particularly when there is a need to avoid inbreeding. In animal breeding, ''crossbreeds'' are crosses within a single species, while '' hybrids'' are crosses between different species. In plant breeding terminology, the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars. Horticulturists generally believe the word ''cultivar''''Cultivar'' () has two meanings, as explained in ''Formal definition'': it is a classification category and a taxonomic unit within the category. When referring to a taxon, the word does not apply to an individual plant but to all plants that share the unique characteristics that define the cultivar. was coined as a term meaning "cultivated variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breeds
A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist several slightly deviating definitions. Breeds are formed through genetic isolation and either natural adaptation to the environment or selective breeding, or a combination of the two. Despite the centrality of the idea of "breeds" to animal husbandry and agriculture, no single, scientifically accepted definition of the term exists. A breed is therefore not an objective or biologically verifiable classification but is instead a term of art amongst groups of breeders who share a consensus around what qualities make some members of a given species members of a nameable subset. Another point of view is that a breed is consistent enough in type to be logically grouped together and when mated within the group produce the same type. When bred together, indiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domesticated Plants
This is a list of plants that have been domesticated by humans. The list includes individual plant species identified by their common names as well as larger formal and informal botanical categories which include at least some domesticated individuals. Plants in this list are grouped by the original or primary purpose for which they were domesticated, and subsequently by botanical or culinary categories. Plants with more than one significant human use may be listed in multiple categories. Plants are considered domesticated when their life cycle, behavior, or appearance has been significantly altered as a result of being under artificial selection by humans for multiple generations (see the main article on domestication for more information). Thousands of distinct plant species have been domesticated throughout human history. Not all modern domesticated plant varieties can be found growing in the wild; many are actually hybrids of two or more naturally occurring species and therefo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domesticated Animals
This page gives a list of domesticated animals, also including a list of animals which are or may be currently undergoing the process of domestication and animals that have an extensive relationship with humans beyond simple predation. This includes species which are semi-domesticated, undomesticated but captive-bred on a commercial scale, or commonly wild-caught, at least occasionally captive-bred, and tameable. In order to be considered fully domesticated, most species have undergone significant genetic, behavioural and morphological changes from their wild ancestors, while others have changed very little from their wild ancestors despite hundreds or thousands of years of potential selective breeding. A number of factors determine how quickly any changes may occur in a species, but there is not always a desire to improve a species from its wild form. Domestication is a gradual process, so there is no precise moment in the history of a given species when it can be considered to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selective Breeding
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals. In animal breeding, techniques such as inbreeding, linebreeding, and outcrossing are utilized. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been successful in producing change over time in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfdog
A wolfdog is a canine produced by the mating of a domestic dog (''Canis familiaris'') with a gray wolf (''Canis lupus''), eastern wolf (''Canis lycaon''), red wolf (''Canis rufus''), or Ethiopian wolf (''Canis simensis'') to produce a hybrid. Admixture There are a range of experts who believe that they can tell the difference between a wolf, a dog, and a wolfdog, but they have been proven to be incorrect when providing their evidence before courts of law. Admixture between domestic dogs and other subspecies of gray wolves are the most common wolfdogs since dogs and gray wolves are considered the same species, are genetically very close and have shared vast portions of their ranges for millennia. Such admixture in the wild have been detected in many populations scattered throughout Europe and North America, usually occurring in areas where wolf populations have declined from human impacts and persecutions. At the same time, wolfdogs are also often bred in captivity for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beefalo
Beefalo constitute a hybrid offspring of domestic cattle (''Bos taurus''), usually a male in managed breeding programs, and the American bison (''Bison bison''), usually a female in managed breeding programs. The breed was created to combine the characteristics of both animals for beef production. Beefalo are primarily cattle in genetics and appearance, with the breed association defining a full Beefalo as one with three-eighths (37.5%) bison genetics, while animals with higher percentages of bison genetics are called "bison hybrids". History Accidental crosses were noticed as long ago as 1749 in the Southern states of North America, during British colonization. Cattle and bison were first intentionally crossbred during the mid- 19th century. One of the first efforts to cross-breed bison and domestic cattle was in 1815 by Mr. Robert Wickliffe of Lexington, Kentucky. Mr. Robert Wickliffe's experiments continued for up to 30 years. Another early deliberate attempt to cross-br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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