Concept
Phenotypic trait
Overview
A phenotypic trait, simply trait, or character state is any distinct variant of a phenotypic, or observable, characteristic of an organism; it may be either inherited or determined environmentally but typically occurs as a combination of the two. For example, having eye color is a character of an organism, while blue, brown and hazel versions of eye color are traits. The term trait is generally used in genetics, often to describe the phenotypic expression of different combinations of alleles in different individual organisms within a single population, such as the famous purple vs. white flower coloration in Gregor Mendel's pea plants. By contrast, in systematics, the term character state is employed to describe features that represent fixed diagnostic differences among taxa, such as the absence of tails in great apes, relative to other primate groups.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
Found by search and not yet checked by a person; they may only mention the idea in passing.
Nor shall I here discuss the various definitions which have been given of the term species. No one definition has as yet satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation. The term “variety” is almost equally difficult to define; but here community of descent is almost universally…
Charles Darwin, On the Origin of Species By Means of Natural Selection
States what Phenotypic trait is.
Though unlikeness among progenitors is one antecedent of variation, it is by no means the sole antecedent. Were it so, the young ones successively born to the same parents would be alike. If any peculiarity in a new organism were a direct resultant of the structural differences between the two organisms which produced it; then all subsequent new organisms produced by these two would show the same peculiarity. But we…
Herbert Spencer, The Principles of Biology, Volume 1
States what Phenotypic trait is.
You will, therefore, find that these things do not follow a fixed law, although their entire absence is just as impossible as the absence of different complexions and of different kinds of hair amongst human beings. In man there are substances the individual existence of which is permanent, and there are other substances which are only constant in the species not in the individuals, as, e.g., the four humours. The…
Moses Maimonides, The guide for the perplexed
Close in meaning to Phenotypic trait; the term itself is not named.
Related ideas
Place in the tradition
Part of Consciousness.