Biological Classification – Solutions

1.Discuss how classification systems have undergone several changes over a period of time?
Solution:
Different systems of classification proposed from time to time have undergone several changes with the change in the parameters use for classification, ranging from the artificial system to the natural system to the phylogenetic system.
Earlier systems of classifications were on one or more convenient morphological characters. For example, plants were classified as herbs (plants with weak stem), shrubs (plants with bushy appearance, and much more branched, short height) and trees (plants with a hard stem, developed branches) on the basis of their habit. Animals, on the other hand were classified as aquatic (water dwellers), terrestrial (land dwellers) and aerial (air dwellers). This classification system is referred to as the “artificial system of classification”. These systems were then followed by the “natural system of classification” that is based on a number of structural and morphological taxonomic characters.
Now a days, organisms are classified on the basis of their evolutionary interrelationship. Such a classification system is known as the “phylogenetic system of classification.” This system incorporates the evolutionary relation apart from gross morphology and other characteristics like cell structure, nature of cell wall, mode of nutrition, habitat, methods of reproduction, etc.