ON THE SHAPES OF LEAVES

The properties of a function G(x, y) of 2-dimensional Cartesian coordinates x, y can be used to obtain complex shapes through a nonlinear iterative procedure. It is conjectured that at least some biological shapes are determined by this procedure, and those of leaves are considered as a test of the hypothesis. It is shown that this procedure will generate the shapes of even very complicated leaves such as those of the holly tree to a considerable degree of accuracy. Certain issues of evolutionary biology appear in our view in a clearer light according to this procedure, and these are discussed towards the end of the paper. (C) 1994 Wiley-Liss, Inc.