abstract = "Modularity represents a recurring theme in the attempt
to scale evolution to the design of complex systems.
However, modularity rarely forms the central theme of
an artificial approach to evolution. In this work, we
report on progress with the recently proposed Tangled
Program Graph (TPG) framework in which programs are
modules. The combination of the TPG representation and
its variation operators enable both teams of programs
and graphs of teams of programs to appear in an
emergent process. The original development of TPG was
limited to tasks with, for the most part, complete
information. This work details two recent approaches
for scaling TPG to tasks that are dominated by
partially observable sources of information using
different formulations of indexed memory. One
formulation emphasizes the incremental construction of
memory, again as an emergent process, resulting in a
distributed view of state. The second formulation
assumes a single global instance of memory and develops
it as a communication medium, thus a single global view
of state. The resulting empirical evaluation
demonstrates that TPG equipped with memory is able to
solve multi-task recursive time-series forecasting
problems and visual navigation tasks expressed in two
levels of a commercial first-person shooter
environment.",