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
Non-reproductive sexual behavior in animals one of these two bonding. Homosexual parenting is very common, especially in birds. Homosexual pairs have better skills and larger nests than heterosexual pairs. Homosexual pairing can occur different ways, one example would be two female animals with offspring coming together and helping each other raise their offspring. Genital-genital rubbing, or GG rubbing, among non-human animals is sexual activity in which one animal rubs his or her genitals against the genitals of another animal. The term "GG rubbing" is frequently used by primatologists to describe this type of sexual intimacy among female bonobos, and is stated to be the "bonobo's