FROM WIGGLESWORTH TO TURING

The orderings, and orderings of orderings, that go into the generation of a human body, or even of much less complex organisms, make any catalogue of catalogues or bibliography of bibliographies look like rather simplistic stuff. It is unsurprising that much enlightenment on what is happening is derived from what happens when something goes wrong. The usual major defects known as mutations have been of enormous value in genetics. Thus, rather confusingly for anyone approaching the field for the first time, many Drosophila genes are named negatively, for what happens when they are not working: fushi tarazu, Japanese for ‘not enough segments’, is working properly when the insect produces exactly enough segments; likewise for hunchback, Krüppel (German for cripple) and so forth. Also, experiments in developmental biology often involve transplanting pieces of tissue to places in an organism that Nature, with her zeal for self-organization, would not have thought of.

But if perfect orderings are the ideal, Nature sometimes seems to persist in ‘going wrong’ by keeping on doing something rather sloppily. A kind of sloppiness that is potentially informative is imperfect ordering of a pattern, in which numerous parts (usually ‘spots’ on a more or less flat surface) are neither randomly distributed nor marshalled into square or hexagonal ordering, but something in between.