Characters

Abstract

In genetics, the term ‘character’ is applied to any property of an organism in regard to which similarities or differences, especially those of a heritable nature, are recognizable between individuals. A great variety of characters is known to show heritable variation and as our knowledge of the properties of living organisms grows, the list of their characters having heritable variations grows with it. Gene and chromosome behaviour, cell shape and structure, gross morphology, physiological and biochemical properties, psychological and behavioural characteristics, mating capacity and propensity, fertility, resistance to disease and toxic agents, ability to infect a host, ability to act as a vector of disease, antigen production: all are known to show heritable variation. Indeed the proposition can hardly be questioned that no character of any organism would fail to show heritable variation were it subjected to adequate examination. Furthermore, the magnitude of the heritable differences shown in a character may range from the smallest that is detectable to the largest that is possible.