Abstract
This paper investigates how environmental structure, given
the innate properties of a population, affects the degree to
which this population can adapt to the environment. The
model we explore involves simple agents in a 2-d world
which can sense a local food distribution and, as specified
by their genomes, move to a new location and ingest the
food there. Adaptation in this model consists of improving
the genomic sensorimotor mapping so as to maximally
exploit the environmental resources. We vary
environmental structure to see its specific effect on
adaptive success. In our investigation, two properties of
environmental structure, conditioned by the sensorimotor
capacities of the agents, have emerged as significant factors
in determining adaptive success: (1) the information
content of the environment which quantifies the diversity of
conditions sensed, and (2) the expected utility for optimal
action. These correspond to the syntactic and pragmatic
aspects of environmental information, respectively. We find
that the ratio of expected utility to information content
predicts adaptive success measured by population gain and
information content alone predicts the fraction of ideal
utility achieved. These quantitative methods and specific
conclusions should aid in understanding the effects of
environmental structure on evolutionary adaptation in a
wide range of evolving systems, both artificial and natural.