
92 ◾ Biological Computation
evolutionary change by natural selection of nondirectional (random) varia-
tions. For our discussion it is important to emphasize the following points:
1. Genetic change can result from one of two events: A mutation,
which is a discrete random change in the genetic material that causes
a change in a trait (e.g., color change), or, in sexually reproducing
organisms, via a new combination of alleles.
Germline cells
Development
Mature form
Heredity
Events occurring
in the phenotype
Mutation
FIGURE 3.2 Information transfer in asexual reproduction. e hereditary con-
tinuity is based on reproductive (germ line) cells.