D'Arcy Wentworth Thompson (1860–1948) was a pioneer in mathematical biology, best known for his classic
On Growth and Form (1917). He showed that in several classes of organisms, notably fish, the morphology of related species could be generated by simple geometric transformations. This Demonstration considers a subset of these, namely affine transformations—rotations, scaling, and shearing—that are readily carried out by
Mathematica. These can be represented by a matrix equation

, in which you control the rows

and

by dragging two locators.