Variation (for selection) is created by recombining what has gone before into novel arrangements. This includes novel arrangements of meaning and novel arrangements of meaning with regard to the context in which they function. The biological analogues of these are, on the one hand, genetic mutation and recombination, and on the other hand, the diffusion of species to new habitats, such as the expansion of plants, invertebrates and vertebrates from aquatic into terrestrial environments.
(1) Recombining Potentials
New variants of a model can be created by recombining meanings within the model.[1] If the degree of recombination is sufficient, the result may be a model that can no longer be considered a variant of the original. In science, this can happen when students rebel against a research tradition and build a model on the basis of new questions. As Bronowski[2] urges:
It’s important that students bring a certain ragamuffin irreverence to their studies. They’re not here to worship what is known, but to question it.
(2) Recombining Potential And Context: Generalisation
One way to create a new model is to take an existing one and spread it to a new context. This is a process of generalisation in the sense that the scope or range of the model is expanded: from the specific functional context in which it evolved into other contexts where other models may have already evolved. A recent example of this is Edelman’s selectionist approach to neuroscience, selectionism having been successful as a model in immunology as well as evolutionary biology. Another example in neuroscience is the technological model of brain function that was mapped across from the field of computer science. A more ancient example is the mapping of body parts onto the landscape, such that rivers, for instance, have heads, mouths and arms. This body-environment mapping was reversed in mediæval Europe, as when the four elements: air, fire, earth and water were mapped onto the body as the four fluids: black bile, yellow bile, blood and phlegm, respectively, yielding the four humours: melancholic, choleric, sanguine and phlegmatic.[3]
Footnotes:
[1] This is easier said than done, of course. Models are basins of attraction: once a model gains currency, it drags other attempts to theorise into it.
[2] The Ascent Of Man episode 11: Knowledge Or Certainty.
[3] Bartlett (2001 :204):
Mediæval thinking was dominated by the theory of ‘correspondences’, derived not from Christian revelation but from the idea, Greek in origin, that an explanation, to be part of the divine plan, had to be economical, symmetrical and æsthetically satisfying. What it ignored was the Greeks’ readiness to test a hypothesis by observation and experiment.