The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Discontinuous variation is variation within a population of a characteristic that falls into two or more discrete classes. Classic examples include such things as eye color in animals and the tall and short pea phenotypes used by Austrian botanist Gregor Johann Mendel. Characteristics that display discontinuous variation are present in one state or another; there is no blending or merging of the different forms possible. Unlike continuous variation, discontinuous variation is displayed by characteristics that are usually controlled by only one or two genes and that have little or no environmental component in their expression. For example, height in humans is a characteristic that shows continuous variation. The maximum height an individual can grow to is governed by the genes controlling the system as well as the intake of food. Thus, an undernourished individual is unlikely to achieve maximum height potential. With eye color, a person's eyes will be a certain color irrespective of any external factors operating. This type of variation is sometimes known as qualitative variation. Discontinuous variation can be produced by a single gene mutation or it can be evidence of a polymorphic gene system.