ABSTRACT
Tigers have stripes and leopards have spots. Darwin’s finches are renowned for the differences in their beak sizes and shapes. The developing fly embryo early after fertilization acquires “stripes” of its own in the form of precursors to its eventual segmented body plan. There are many observable kinds of biological patterns at all spatial scales from molecules to cells to appendages to communities that follow some sort of geometrical rule. Many of the macromolecular assemblies already described throughout the book can be thought of as spontaneously self-organized patterns of interacting molecules, such as virus capsids and microtubules. The existence of pattern and order in the living world is striking to the most casual observer. Not only do living organisms generate regularly spaced structures and markings, like the stripes on a zebra or the petals on a flower, but the structures are also remarkably reproducible.
