Effects of Early‐Life Experience on Learning Ability in Fruit Flies

Abstract Learning and memory require the development, modification and maintenance of brain tissue, which cost time and energy. It may be adaptive for developing animals to adjust such investments based on environmental cues indicating the future utility of learning. The optimal learning ability that maximizes fitness will vary with the degree of complexity or difficulty of the environment, and developing animals may show an adaptive plastic modification of the extent of their learning ability based on early‐life cues of environmental complexity. We tested whether fruit fly larvae reared in a ‘complex’ environment, where they had to search, sample and choose between three foods differing in flavour and bitterness subsequently possessed greater learning abilities than larvae reared in a simple environment with only one food type. We tested learning ability both at the larval stage and in young adults. Our results suggest that, despite theoretical and intuitive appeal, these environmental factors did not affect learning ability.