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Polygenetic Shield Volcanoes
Polygenesis can refer to: * Polygenesis (linguistics), a theory of language origin * Polygenism Polygenism is a theory of human origins which posits the view that the human races are of different origins (''polygenesis''). This view is opposite to the idea of monogenism, which posits a single origin of humanity. Modern scientific views no ..., a theory of human origin * Gene duplication, a form of genetic disorder resulting in the overexpression of a particular gene Gourav * Polygenetic landforms, landforms formed the accumulative action of various processes {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygenesis (linguistics)
In the field of linguistics, polygenesis is the view that human languages evolved as several lineages independent of one another. It is contrasted with monogenesis, which is the view that human languages all go back to a single common ancestor. Polygenesis is not to be confused with the wave theory, originally propounded by Johannes Schmidt. See also *Polygenism * August Schleicher *Ernst Haeckel Ernst Heinrich Philipp August Haeckel (; 16 February 1834 – 9 August 1919) was a German zoologist, naturalist, eugenicist, philosopher, physician, professor, marine biologist and artist. He discovered, described and named thousands of new s ... Historical linguistics Evolution of language Linguistic theories and hypotheses {{historical-linguistics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygenism
Polygenism is a theory of human origins which posits the view that the human races are of different origins (''polygenesis''). This view is opposite to the idea of monogenism, which posits a single origin of humanity. Modern scientific views no longer favor the polygenic model, with the monogenic "Out of Africa" hypothesis and its variants being the most widely accepted models for human origins. Historically, polygenism has been used to advance racial inequality. Origins Many oral traditions feature polygenesis in their creation stories. For example, Bambuti mythology and other creation stories from the pygmies of Congo state that the supreme God of the pygmies, Khonvoum, created three different races of humans separately out of three kinds of clay: one black, one white, and one red. In some cultures, polygenism in the creation narrative served an etiological function. These narratives provided an explanation as to why other people groups exist who are not affiliated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Duplication
Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene. Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage. Mechanisms of duplication Ectopic recombination Duplications arise from an event termed unequal crossing-over that occurs during meiosis between misaligned homologous chromosomes. The chance of it happening is a function of the degree of sharing of repetitive elements between two chromosomes. The products of this recombination are a duplication at the site of the exchange and a reciprocal deletion. Ectopic recombination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
