In the 1940's Barbara McClintock identified a new type of genetic element in corn that she proposed (to the general amazement of the genetics community) to move around within the genome. These "jumping genes" or transposable elements, as they have come to be called, have recently been shown to exist in a wide variety of organisms and are known to cause mutations in the DNA at sites where they insert. As the widespread occurrence of these transposable elements became apparent, their importance as a major source of genetic variation, subject to natural or artificial selection to produce population change, became an issue. The particular aspect of this problem addressed by this project is whether the response to artificial selection for a quantitative trait (an inherited trait controlled by many genes and influenced by environmental factors as well) differs between populations that are genetically identical except for the presence of a particular transposable element. The hypothesis is that mutations caused by the transposable element in genes that affect the quantitative trait might serve as an additional source of usable variation, allowing a greater response to selection to occur in populations containing the element.
