abstract = "The theoretical foundations of genetic algorithms (GA)
rest on the shoulders of the Schema Theorem, which
states that the building blocks, highly fit compact
subsets of the chromosome, are more likely to survive
from one generation to the next. The theory of genetic
programming (GP) is tenuous, borrowing heavily from
that of GA. As the GP can be considered to be a GA
operating on a tree structure, this borrowing is
adequate for most. Part of the problem of tying GP
theory to the schema theorem is in the identification
of building blocks. We discuss how a building block can
be represented in a GP chromosome and the
characteristics of building blocks in GP chromosomes.
We also present the clique detection domain for which
the detection of building blocks is easier than in
previous domains used in GP research. We illustrate how
the clique detection domain facilitates the
construction of fitness landscapes similar to those of
the Royal Road functions in GA research.",