Consider a small vertebrate, maybe a deer mouse, maybe an anole, in need of some food. Usually this animal successfully forages in the low ground such as a gully. However, in this instance, either by error or chance, it searches the high ground such as the top of a small mound. If the high ground is exceedingly rich in food, the “mistake” has positive adaptive consequences not only immediately but also for the future. The animal now has a new food source to exploit. On the other hand, this ven ture may be a failure; the high ground is devoid of food. This may mean no food for a few hours or even a day. Note here that in terms of ulti mate reproductive prospects, the cost of failure for the mistake is not very great. Being hungry for a day probably won’t mean a drastic decre ment in the ability to pass on genes. And if these occasional mistakes pay off once in a while, there may be a net evolutionary benefit to such variability in behavior.