Darwin’s Theory of Development and Evolution

Type:

Book Chapter

Author:

Mary Jane West-Eberhard

Published:

2003

Publisher:

Oxford University Press

Biologists are fond of saying that Darwin was misled by an inadequate theory of inheritance—his the-ory of “pangenesis”—and that this was remedied by the rediscovery of Mendel’s experiments in 1900: . . . As long as no coherent theory of heredity existed, the basis of natural selection could not be understood. Darwin’s theory of pangenesis was an unfortunate anomaly. It was almost his only venture into the field of pure speculation. . . . One might speculate whether Darwin would have formulated his theory of pangenesis if he had been aware of Mendel’s experiments. (J. L. Stebbins, 1977, p. 14; see also, e.g., Mayr, 1963, p. 10; 1966, p. xxvi; Selander, 1972, p. 185) . . . I have argued that some aspects of development can be related to natural selection by visualizing the phenotype as a mosaic of semi-independent sub-units that are dissociated, recombined, lost, and recalled during evolution and that adaptive plasticity plays a role in evolutionary change. Darwin insisted on the same view in The Variation of Animals and Plants under Domestication (1868), where he gave the most complete exposition of his ideas about development and evolution. In a section titled “The Functional Independence of the Elements or Units of the Body,” Darwin (1868a [1875a], p. 364) wrote that “the whole organism consists of a multitude of elemental parts, which are to a great extent independent of one another. Each organ . . . has its proper life, its autonomy; it can develop and reproduce itself…

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