“The effect of scale depends not on a thing in itself, but in relation to its whole environment or milieu. It is in conformity with the thing’s place in nature, its field of action and reaction in the universe. Everywhere nature works true to scale, and everything has its proper size accordingly” – D’Arcy Thompson. On Growth and Form 1917.
Welcome to Biological Scaling!
One of the central problems of biology is how to connect pattern and process that operate at differing temporal and spatial scales. Scaling is a powerful approach by which to mechanistically link biological phenomena across differing ‘scales’ of measurement (e.g. geographic, temporal, and organismal size). As such, it is increasingly becoming a central component of integrative biology, ‘biocomplexity’, ecology, and evolutionary biology. More importantly it offers a quantitative/predictive framework by which to connect attributes of anatomy, physiology, ecology, and evolution – over space and time.
As one changes the scale of a point of reference, measurement unit, or variable aspect of a given system, one often observes dynamic changes or prominent regularities in that system. For example, in a pond, the physical environment encountered at small scales by small organisms differs dramatically in the forces of surface tension, viscosity . . . . from the environment experienced by larger organisms at larger scales. This is often termed physical similarity between scales. However, across the same scales of organisms, biological systems can share identical regularities that do not change with scale. It is the intent of this course to highlight some of the prominent issues that emerge as one investigates how systems change with scale.