Making sense of Genotype-Phenotype Distinction, another version (7)

Comments welcome by anyone interested to read the revised draft, which begins:

The predominant current-day meaning of genotype is some relevant part of the DNA passed to the organism by its parents. The phenotype is the physical and behavioral traits of the organism, for example, size and shape, metabolic activities, and patterns of movement. The distinction between them is especially important in evolutionary theory, where the survival and mating of organisms depends on their traits, but it is the DNA, held to be unaffected by the development of the traits over the life course, that is transmitted to the next generation.

Philosophical discussion mostly now takes the predominant meanings as given, focusing instead on questions about the genotype-phenotype relationship. For example: How can DNA be construed as information for the processes of development of an organism’s traits? What is the causal status of DNA versus other influences in the organism’s development? (See Inheritance Systems, Biological Information, Griffiths and Stotz 2103).

Without dismissing the importance of such questions, the focus of this entry remains on the genotype-phenotype distinction. Given that discussion by philosophers of this issue has been minimal, this entry cannot take the standard form of a review of published debates. In order to frame and orient readers’ conceptual inquiries, another approach is needed. The entry builds from the observation that the original meanings of genotype and phenotype and the distinction between them as given by Johannsen (1911) were quite different from the now predominant meaning (given above) and that different kinds of meanings coexist in Johannsen and up to the present. To make sense of that observation, a conceptual history is recounted with special reference to practices or assumptions regarding control of biological materials and conditions that have been involved in the original formulation of the terms and their distinction and since.

This framing brings into play many areas of philosophical discussions, including the “New Experimentalism” in philosophy of biology (see Experiment in Biology), abstraction (see Abstract objects), confirmation, ambiguity, Scientific Realism, descriptive versus normative approaches, and The Social Dimensions of Scientific Knowledge.


Underlined terms refer to entries in Stanford Encyclopedia of Philosophy

Griffiths, P. and Stotz, K., 2013, Genetics and Philosophy: An Introduction, Cambridge: Cambridge University Press.

Johannsen, W. (1911). “The Genotype Conception of Heredity.” The American Naturalist 45: 129-159.

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