Taxonomy of Finfish

1.2.11 Periods of classification

1. First period

Even the primitive tribes were often excellent naturalists. Hippocrates (460 – 377 B.C) enumerated different kinds of animals. Aristottle (383 – 322 B.C) was the Father of Classification. He described that animals can be characterized according to their way of living, their action, their habits and their bodily parts. However, he did not supply an orderly, fully consistent classification of animals. Of all the preLinnaean authors, the one who arrived at the most Natural Higher Classification was John Ray (1627 – 1705).

2. Second period (Linnaean and his contemporarian)

The great Swedish naturist Linnaeus (1707 – 1778) exerted such an important influene on the entire subsequent development of classification of organisms. Hence, he was called”Father of Taxonomy”. The binomial method of nomenclature was for the first time applied by him to the animals in the 12th edition of his “Systema Naturae” (1758).

He followed Aristottle’s idea of the essential features of living things and his logic.

3. Third period (The empirical approach)

The hundred years between the 12th edition of his “Systema Naturae” and the publication of “Darwin’s origin of species” was a period of subtle. Lamarek (1744 – 1829) who lived during this period had no visible influence on these developments except for some purely practical contribution he made to the classification of invertebrates. Cuvier (1789 – 1832) was far more influential during this period. A steady and enormous increase in the number of known animals characterized this period.

Voyages all over the globe acquainted zoologists with the animals of Africa, Australia and America.

4. Fourth period (Darwin and phylogeny)

Charles Darwin encountered so many phenomena of distribution, variation, structure and adaptation during his voyage. Taxonomists began to accept evolution. The German biologist Ernst Haeckel proposed the term ‘protista’. His phylogentic trees and speculations greatly stimulated the taxonomy.

5. Fifth period (Population systematics)

Study of intraspecific variation was the objective of population systematics. It is not an alternative to classical taxonomy but only an extension.

6. Sixth period

This period is characterized by renewed examination of whole theory of taxonomy and development of biochemical and molecular markers to study the intraspecific variation.