Artificial selection

In summary, the life cycle of S. ratti contains a switch between two developmental routes. The developmental propensity phenotype varies between different isofemale lines and this can be altered by artificial selection. This shows that there is diversity for this trait both within and between parasite... 

Hill, W.G. and Caballero, A. (1992) Artificial selection experiments. Annual Review of Ecology and SystematicsTi, 287-310. 

Plant breeding the purposeful manipulation of plant species in order to create desired genetic modifications for specific purposes. This manipulation usually involves either cross- or self-pollination, followed by artificial selection of progeny. 

Domestication of plants an artificial selection process carried out by humans to produce plants that have fewer undesirable traits of wild plants, and which renders them more dependent on artificial (usually enhanced) environments for their continued existence. The practice is estimated to date back 9,000—11,000 years. Today, all of our principal food crops come from domesticated varieties. Over the millennia many domesticated species have become utterly unlike their natural ancestors. Corn cobs are now dozens of times the size of their wild ancestors, producing seeds that are more digestible (figure 4.2). 

Domestication An artificial selection process to produce plants that have fewer undesirable traits. 

Hybridization The production of offspring (hybrids) from genetically unlike parents, by natural processes or by human intervention (i.e., artificial selection). In plant breeding, includes the process of cross-breeding two different varieties to produce hybrid plants. If the hybrid is more fit than either parent the condition is called hybrid vigor (or heterosis). Hybrid offspring may result from gene flow between domesticated crops and wild relatives. 

Gibson, J. M. (1989). Simulated evolution and artificial selection. BioSystems, 23,... 

Of all individual features that distinguish an animal from the others, many are found again in its descendants, and are therefore inherited. These two facts are precisely what allows breeders to practise the artificial selection of animals with great success, and Darwin concluded... 

The section on synthesis has been limited to preparations of a particular type of labeled cyclopropane, for reasons detailed in Section II. The uses of labeled cyclopropanes have been interpreted in an almost exclusively mechanistic sense. Within this context reactions involving labeled cyclopropanes as reactants, intermediates, or products have been considered. Finally, it is worth noting that the definition of the material to be included in this chapter has sometimes resulted in a rather artificial selection of material on related mechanistic problems. Those readers who have carried out elegant mechanistic work with cyclopropanes that did not happen to carry isotopic labels at the positions specified above should therefore not feel slighted by the omission of their work. 

Livestock are domesticated species, which have been genetically modified over time through the artificial selection of desirable traits by humans, with a view to increasing the docility of the animals, their size and productivity, their quality as agricultural products, and other culturally desired features. Some species of livestock no longer occur in their original, non-domesticated, free-living form, and they are totally dependent on humans for their continued existence. However, humans are also substantially dependent on their livestock for sustenance and other purposes. Consequently, the symbiotic relationship between humans and their domestic livestock could be termed a mutualism, that is, a mutually beneficial relationship between two species. 

Artificial Selection y Wildtype Quasispectes fSite specific Mutagenesis) V Natural Selection "m" outgrows "k"... 

Price T, Schluter D 1991 On the low heritability of life history traits. Evolution 45 853-861 Rowe L, Houle D 1996 The lek paradox and the capture of genetic variance by condition dependent traits. Proc R Soc Lond B Biol Sci 263 1415—1421 Taylor PD, Williams GC 1982 The lek paradox is not resolved. Theor Pop Biol 22 392—409 Wilkinson GS, Reillo 1994 Female choice response to artificial selection on an exaggerated male trait in a stalk-eyed fly. Proc R Soc Lond B Biol Sci 255 1—6... 

Some predictions for [Eu/Fe] have been made recently by [67]. They are based on a homogeneous one zone model in which it is assumed that stars in prescribed mass ranges produce an artificially selected amount of r-nuclides through the neutrino wind or prompt explosion mechanisms (Sects. 4 and 8). As expected, the predicted [Eu/Fe] ratio is very sensitive to the selected stellar mass ranges. This result might be optimistically considered as providing a way to constrain the site(s) of the r-process from observation. Reality is most likely less rosy, as very many uncertainties and severe approximations drastically blur the picture. 

The basic strategy of plant biotechnology is a refinement of plant breeding and hybridization techniques practiced since the dawn of agriculture. The principle is that of natural selection and is the same that occurs in evolution. Plant breeders artificially select individual plants with desirable characteristics rather than letting the environment select the hardiest plants for survival. The desirable characteristics differ between individuals because each of different genes produces different inherited properties (phenotypes) in the new generation of plants. 

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