Why Do We Classify? The Need for Classification

With well over a million and a half species already known — and uncounted more awaiting discovery — no single biologist, however dedicated, could hope to study each organism individually and remember its features in isolation. If every organism were treated as a completely unconnected case, biology as a science would be impossible to organise, teach, or communicate. Classification solves this problem: it is the process of arranging organisms into convenient, systematic groups on the basis of characters they share, so that similar organisms are placed together and dissimilar ones are kept apart.

The need for classification arises from several practical and scientific demands:

• It makes the identification of an organism possible — once we know which group an organism belongs to, we automatically know a great deal about its likely structure, habits, and relationships, without having to study it from scratch.
• It brings order to an otherwise overwhelming diversity, turning millions of individual facts into a manageable, searchable system, much as a library catalogue lets you find one book among millions.
• It allows the storage and retrieval of biological information efficiently, since related organisms sharing similar characters can be studied, taught, and referenced together.
• It reflects genuine biological relationships. Grouping is never arbitrary — organisms are placed together because they share real, inherited features, so a good classification system doubles as a working hypothesis about how different organisms are related to each other.
• It supports every other area of biology — agriculture, medicine, conservation and pest control all depend on being able to correctly identify an organism before deciding how to grow it, treat it, protect it, or control it. …