One Biologist's View of Morphometrics

For this biologist, morphometrics is the characterization of biologically relevant forms and patterns in ways that allow their quantitative handling: a considerably wider definition than usual. There are many different methods by which we may carry out this characterization, many different types of structure to be characterized, and many different ways in which the results may be used within systematics and evolutionary biology. The methods range from the use of a measurement and univariate statistics, to holographic techniques. The forms to be characterized may be the external dimensions of some simple biological object, the complex internal patterns revealed by such methods as dissection and radiography, or the complicated and multidimensional "structure" of data relevant to a biological problem. Problems of systematics and evolution may be attacked through straightforward descriptions of organisms on the one hand, or, on the other, through elucidation of the conceptual patterns associated with ontogenetic, genetic, phylogenetic, functional, environmental, populational, geographic, and other issues. At the beginning of the century when the science of morphometrics was still in its infancy, Karl Pearson prophesied that "Twenty years hence our successors, working by improved methods and with better training, will no doubt reach fitter definitions and more exact values for vital coefficients." He added that by this time, morphometric methods will not "have to justify themselves to a non-mathematical biological world; mathematical knowledge will seem to be as much a part of the biologist's equipment as today of the physicist." Yet in spite of what may appear to be an enormous spate of papers using morphometric approaches, seventy years later it is still scarcely appropriate to review the contributions of morphometric techniques to biological thought. Many of the