Chapter 2

Genotype, Phenotype, and Environment

Whenever confronting the totality of biology, it is clear that one may approach it at

various levels, such as molecular, cellular, organismal, populational, and ecological.

Traditionally, these levels have been accorded official status by naming academic

departments after them. Just as we shall see in Part II, especially Chap. 6, with the

levels of information (technical, semantic, effective), however, one quickly distorts

a vision reflecting reality by insisting on the independence of the levels. For exam-

ple, it is not possible to understand how populations of organisms evolve without

considering what is happening to their DNA molecules.

The basic unit of life is the organism, which has, of course, a physical reality. This

reality can be observed as the phenotype, which may be defined as the organism

interacting with its environment. Insofar as phenotype also encompasses behaviour,

there may be aspects of it, such as those involved inner thought, that are not observ-

able (Ramsden 2001). But much of phenotype is in some sense “specified” by an

organism’s genotype—the set of alleles (different forms of a gene) for a given gene

or set of genes. Genotype is a subset of the genome—the entire genetic material of an

organism, including both genes and non-coding DNA. “Non-coding” means that the

DNA is not “expressed” as a protein, but much of it is involved in regulating expres-

sion. Indeed Schrödinger (1944) argued that life is a physical and chemical process

regulated by the genetic code (and “feeding” on entropy in order to maintain order

within the organism via the processes of metabolism, growth, and reproduction). The

DNA is of course the heritable material that is passed on to progeny (but offspring

brought up in the environment of their parents will also, in effect, “inherit” many

aspects of behaviour and thought from them; the extent of this inheritance can be

extended to cultural features of the society in which the organism is living). Indeed,

it has been asserted that DNA is merely the medium of storage of information that

exists elsewhere in the system, to which it has a similar relationship to that of the

library to a university.

© Springer Nature Switzerland AG 2023

J. Ramsden, Bioinformatics, Computational Biology,

https://doi.org/10.1007/978-3-030-45607-8_2

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