MORPHA

MORPHA (from Greek morphe - external appearance, form), form in the broad sense of the word, which encompasses not only external appearance but also the internal structure of the organism. The historically established form of organisms characterizes their given species and is repeated with constancy in each new generation or - at any rate - through a certain series of generations (the phenomenon of alternation of generations). This repetition is not ideally exact, and the observed changes constitute part of the basis for the process of historical development (evolution) of the form of organisms. A more profound analysis, carried out by modern genetics, shows that it is necessary to distinguish some hereditarily determined basis of the structure of a particular organism - its genotype - and the concrete manifestation of this structure in its dependence on variable external conditions - phenotype. Only genotypic changes, characterized by a change in the hereditary substance itself (composition of its genes), can provide material for the historical development of the form of organisms. - Morpha in systematics denotes the smallest taxonomic unit, namely - a subspecies, characterized by specific habitat conditions (ecological form as opposed to geographical).