On the island of Borneo, a primate lives that can spend months at the top of the trees looking for fruit without ever falling to the ground: it is the orangutan.
The primates, well adapted to eating fruits up in the trees, always complement their diet with insects and eggs they occasionally find, and they conserved this custom when they came down from the trees some 15 million years ago.
However, gathering plants sometimes forces them to travel long distances. Droughts began, and the herds had to migrate in search of places with water and vegetation. They were followed by another type of killer, a descendent of vegetarians who had acquired a taste for meat.
Man applied all his intelligence to hunting, inventing all kinds of tricks to compete with the large carnivores. And, like them, he soon realised that the life of the hunter is too uncertain, and that a growing population of humans could not depend exclusively on meat.
The solution was to combine the two systems, to gather fruits, berries, roots and leaves to see them through the long periods of unsuccessful hunting.
In the interior of these jungles on the island of Borneo lives a primate whose knowledge of botany is incredible. It can spent months up in the trees looking for fruit, without ever coming down to the ground. That animal is the orang-utan. But in this world of apparent abundance, gathering plants is not as simple as it seems. Not all the trees bear fruit at the same time, and sometimes not even all the branches of the same tree.
The orang-utan has a memory capable of recognising over 400 different types of food. It must remember the exact place of each species of tree, and the approximate date on which the fruits mature. It must also avoid the poisonous parts of some of them, as well as the thorns or hard skins. All of this it learns from its mother, over years, observing her on her wanderings around the jungle. An efficient gatherer like the orang-utan and like our simian ancestors, must have good sight in order to recognise the bright colours of the fruits in the jungle, while the carnivores see in black and white, giving preference to movement and nocturnal vision. A good gatherer has a discerning palate to distinguish the sweet flavour of ripe fruits, and tastes them to remove the indigestible parts. Carnivores, on the other hand, swallow large pieces of meat without tasting them at all. A gatherer must have hands with agile fingers to peel the fruits and cling on to the branches, whereas a carnivore prefers claws. Finally, a gatherer needs a large, efficient brain to remember ever corner of its habitat.
The orang-utan teaches us that a lot of what we have in common is due to the fact that, like it, we too were once gatherers.