Arboreal theory and feet that were capable of grasping. This was also a result of arboreal life, which required a great deal of crawling along branches, and reaching out for fruit and other food. These early primates were likely to have eaten foods found in trees, such as flowers, fruits, berries, gums, leaves, and insects. They are thought to have shifted their diets towards insects in the early Cenozoic era, when insects became more numerous. 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
Prostitution among animals Prostitution among animals A few studies have suggested that prostitution exists among different species of non-human animals such as Adélie penguins and chimpanzees. The concept is also known as transactional sex. Penguins use stones for building their nests. Based on a 1998 study, media reports stated that a shortage of stones led female Adélie penguins to trade sex for stones. Some pair-bonded female penguins copulate with males who are not their mates and then take pebbles for their own nests. Chimpanzees who appear to be trading food for sex have also been described as engaging in prostitution. Prostitution in animals