Arboreal theory Arboreal theory This theory is proposed by Grafton Elliott-Smith (1912) who was a neuroanatomist who was chiefly concerned with the emergence of the primate brain. The arboreal theory claims that primates evolved from their ancestors by adapting to arboreal life. Primates are thought to have developed several of their traits and habits initially while living in trees. One key component to this argument is that primates relied on sight over smell. They were able to develop a keen sense of depth perception, perhaps because of the constant leaping that was necessary to move about the trees. Primates also developed hands
Structures built by animals amphibians, molluscs, urochordates, crustaceans, annelids and some other arthropods. It is virtually absent from all the other animal phyla. Animals create structures primarily for three reasons: Animals primarily build habitat for protection from extreme temperatures and from predation. Constructed structures raise physical problems which need to be resolved, such as humidity control or ventilation, which increases the complexity of the structure. Over time, through evolution, animals use shelters for other purposes such as reproduction, food storage, etc. Predators are attracted to animal-built structures either by the prey or its offspring, or the stored caches of food. Structures built by animals