  Despite the obvious advantage of simple life forms capable of fast
replication, different levels of cognitive complexity have been achieved by
living systems in terms of their potential to cope with environmental
uncertainty. Against the inevitable cost associated to detecting environmental
cues and responding to them in adaptive ways, we conjecture that the potential
for predicting the environment can overcome the expenses associated to
maintaining costly, complex structures. We present a minimal formal model
grounded in information theory and selection, in which successive generations
of agents are mapped into transmitters and receivers of a coded message. Our
agents are guessing machines and their capacity to deal with environments of
different complexity defines the conditions to sustain more complex agents.
