Final answer:
Garcia's experiment with rats and taste aversion disproved the idea that classical conditioning only works with stimuli presented closely in time, suggesting that there are biological constraints to learning that aid in species survival.
Step-by-step explanation:
The aversion the rats developed in Garcia's experiment disproved the idea that classical conditioning is a simple process that occurs only between paired stimuli that are presented in close temporal proximity. Garcia demonstrated that certain associations, such as taste and illness, could be learned with an extended time lapse between the event (the taste) and the negative stimulus (illness), which is atypical of traditional classical conditioning models. This suggests that there are biological constraints on learning and that organisms are evolutionarily predisposed to make particular associations more easily than others, in this case, the association between taste and sickness. This finding provides evidence for a biologically prepared learning process that can contribute to species survival by helping organisms avoid harmful substances.