Laboratory populations, genetic

Many species of parasitic nematodes are maintained in the laboratory in host species in which they are not found in nature. This has the potential consequence that the laboratory population is, in some way, different from the natural population. Transfer and adaptation of a parasite from a natural host into a different species in the laboratory entails a process of selection. The selection will act on the trait ability to survive in a nonnatural host . Most of the parasite population may have had little, or indeed no, ability to survive in the non-natural host. Thus, at its most extreme form, this selection will have been for the very small proportion of the parasite population with the ability to survive in a non-natural host. A consequence of this is that the parasite population will have gone through a genetic bottleneck. 

Maxwell P. Lee Laboratory of Population Genetics, National Cancer Institute, Bethesda, MD... 

Evolution by natural selection takes place through the success and failure of individuals to survive and reproduce. It thus involves the lowest level of taxonomic structure - the individual. To understand many of the processes of evolution at higher taxonomic levels, it is necessary to study and understand the behaviour of populations and individuals in nature and the laboratory to record their survival and measure their fitness. This study of the interaction between individual fitness and genetic variation lies within the field of population genetics. 

Genetic applications of molecular technologies have different concerns than routine clinical laboratory testing because results are used in a predictive manner (e.g., the probability that a gene is present and, if present, whether it will be expressed and to what extent of severity). Therefore, validation procedures may differ, depending on whether the test will be used in high-risk situations or in the general population. 

They utilize genetically homogeneous laboratory stock test populations ... 

Caucasian. In the United States, most testing clients are, like the majority of the population, Caucasian non-Jews. This is important for the testing laboratory to know because the Bayesian for carrying a common disease allele, such as that causing cystic fibrosis, differs from that of Ashkenazi Jews, Asians, or African Americans. In addition, Caucasian non-Jews of Northern European descent are more prone to different genetic diseases, such as hemochromatosis, than are individuals of other ethnicities. 

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