Why statistics?

The first problem that most students of biology have with statistics is in understanding why they need to study the subject at all. It is possible, during the first few years of biology at school, to learn a great deal about animals, plants and biological systems in terms of discoveries made by biologists in the past. It takes more than this, however, to make a real biologist. A biologist must understand how biological knowledge has been obtained and is being constantly modified and extended by research. It is here that an appreciation of the role of statistics becomes meaningful. For a biologist aiming to make his or her own contribution to biological knowledge some understanding of statistics is essential.

An appreciation of the role of statistics in biology comes most easily through personal involvement in biological investigation, hence the importance of project work, provided that its objective is to discover something new. In part, the role of statistics is direct, enabling us to make statements and draw conclusions of scientific significance from the limited evidence we have obtained by the examination of one or more relatively small samples. For example, suppose as part of a study of the effect of geographical isolation we wish to make statements about the body measurements of the population of field mice on a certain island. We could never hope to catch all of the mice, there might be many thousands, so we trap a sample of them (perhaps 50) and measure this representative group.