This algorithm, which had been inspired by the two evolutionary phenomena of mutation and selection, is based on a simple genotype-phenotype model. In its simplest form, it comprised two procedures: The first reproduces the genotype, thereby creating new individuals with stochastic mutations. The second consists in a developmental programme whereby the genotype is translated according to a recursive tree-drawing scheme with the genes' values used as parameters (depth of recursion, directions of branches). The genotype consists of nine genes, one of which determines the depth of recursion. The other genes are translated into components of a matrix d which represent the horizontal, resp. vertical setoffs in a global coordinate system to be used for the growing binary tree.
This project contains an implementation of the "Blind Watchmaker" algorithm as a relational growth grammar in the language XL (see the file Biomorph.xl). When the relational growth grammar is initialised, four individual biomorphs are created and shown in the 3D view.
You can select one individual by clicking on the small sphere at its base. Now ensure that the panels of the RGG layout are visible (choose this layout in the menu Panels/Set Layout). You will see the RGG toolbar with the buttons run, Run run, Stop, and Reset. A click on run then creates a new generation of individuals based on the genome of the selected parent (asexual reproduction). If you select two individuals (the Ctrl key has to be pressed while clicking the second individual) and invoke run, the genomes of both parents are combined in a crossing-over step, then a new generation is created (sexual reproduction).
Accumulated mutations in a certain direction (biassed by the user) lead to a shortcut through the multidimensional genotypic and phenotypic parameter space, thereby arriving at "biomorphs", i.e. structures that look like animals or plants or possess other, "strange" morphologies.