Temerin et al. One response to this is to limit travel speeds. It is, however, both highly specialized in its anatomy and fairly lethargic, climbing slowly and deliberately. That is, the fruitarian program alleging we are adapted to eat a diet of fruit lacks substantial awareness of the real- world needs of animals who eat high percentages of fruit to be able to efficiently collect that fruit. Finally, the question of whether a fruitarian diet could supply the nutrition needed to drive brain evolution must be considered.
All available evidence indicates that the answer is no.
Getting enough fruit to survive on, every day of the year, is unlikely even in a pristine, primary tropical rainforest. Preceding sections have discussed that orangutans apparently cannot get enough fruit in their remote tropical rainforest homes to live on fruit all year. Finally, no doubt some fruitarian extremists will claim that adequate fruit to support pure fruit diets was in fact available in prehistoric times. This is of course nothing but speculation, without reference to any kind of credible paleobotanical evidence. The obvious conclusion is that a pure fruitarian diet is not feasible for hunter- gatherers or our prehistoric ancestors, as fluctuations in the fruit supply make survival on a pure fruitarian diet unlikely in the short run, and a virtual impossibility in the long run.