Evolution of habitat selection: stochastic acquisition of cognitive clues?

Different habitat preferences in animals have been interpreted mostly as a result of different adaptive design of the species and/or as a result of in terspecific competition. We propose an alternative view of evolution of hab itat preferences. Our model is based on progressive stochastic acquisition of cognitive clues discriminating habitat features which correlate with exp ected fitness. We assume that acquisition of each cognitive clue allowing d iscrimination of 'better' and 'worse' habitats (according to the average fi tness in each habitat) will constrain further evolution, because each furth er clue will discriminate habitats only within previously acquired preferen ces. Simple simulation model shows that if it is the case, even the species with equal habitat-related fitness differences will rapidly diversify in t heir habitat preferences. Therefore, similarly as in the evolution of other species-specific traits, the evolution of animal-habitat relationship may be strongly affected by stochastic events and historical contingency.