Figure 2.

Knowledge acquisition in a changing environment (simulation). Four groups of individuals aim to maximize their knowledgeability about locally available food resources, while minimizing the risk of testing unknown foods. (a)–(c) show four independent groups of 40 individuals: a highly predictable group which does very little experimentation; a highly unpredictable group; and two mixed groups. The mixed groups contain mainly predictable individuals, with either 2 or 10 unpredictable individuals. (a) illustrates the paradigm. At any time, four foods (shown as four letters) are available to be freely chosen. This shows the accuracy of the group's knowledge of available foods, which changes as time progresses during a single run (unspecified time units, t.u.). Error increases each 10 t.u. when one food is replaced by another of unknown quality. Error then reduces as each group learns about the new food. (b) illustrates the rate of acquisition of knowledge of food by the four groups. The highly predictable group acquires information slowly, because individuals always choose their favourite three foods, so rarely explore new ones. (c) shows the gradual loss of individuals by each group, over nine food changes with no offspring (mean of 40 runs). In this particular task, groups in which 5% of the individuals are unpredictable survive the best. For discussion see text; for details see appendix A.