  Darwin's book, Origin of the Species has been a source of public controversy
for more than hundred and fifty years. Court cases and mountains of words have
not dispelled this controversy. In this paper, a quantitative approach using
simple mathematics shows that the concept of evolution by natural selection
using only random choice of variables does work. The procedure applied to the
optical equations forming the phenotype of a spider eye produces an eye design
modeled after the measurements by Land and Barth.
