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Genetics (Greek, ‘study of basic creation-units’) is the study of heredity. The term was introduced by William Bateson in 1905 to refer to the rapidly expanding field which had emerged after the rediscovery of Gregor Mendel\'s work. The science of genetics was founded on the idea that inheritance and variation are the result of the same process rather than the result of two opposing mechanisms. At this time, experimental genetics was concerned with the study of offspring from particular matings. It rapidly became clear that, though Mendel\'s results were correct, some of his conclusions were oversimplified; this was largely due to his restricting his studies to the pea plant. The use of the microscope and of techniques such as radioisotopic labelling enabled the genes to be localized to the chromosomes which are found in the cell nucleus. The American geneticist T.H. Morgan elucidated the role of the chromosomes in heredity. Biochemical approaches to genetics enabled a structure for DNA to be determined which was compatible with the known pattern of DNA replication. This led to a massive expansion of molecular biology, a field which is now synonymous with biochemical genetics, and to the application of this knowledge to industry, medicine and agriculture. The genetic make-up of a group of individuals is termed population genetics and is closely related to evolution; Darwin\'s theory of evolution recognized the existence of heredity but his explanation for the mechanism (blending inheritance) was incorrect. Genetics has filled this gap and the study of populations of plants and animals appears to bear out the principles of evolution. RB
See also Darwinism; gene; genetic code; Mendelism; mutation; natural selection.Further reading Bruce Alberts, The Molecular Biology of the Cell; , Richard Dawkins, The Selfish Gene. |
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