The Circle of Life

The circle of life of most living things is composed of layer upon layer of cycles of growth, development, reproduction, death, and re-birth. The complex matrix of life’s layers is depicted in Ketutski’s painting. Most mammals have two stages of life after birth: infancy when they are fed via lactation by the mother and adulthood when they mate, reproduce and care for their own offspring. The postnatal life cycle of the social mammals, including the nonhuman monkeys and apes, has three basic stages of development: infant, juvenile, and adult. Social mammals not only live in groups but recognize and interact with each other as individuals in complex ways. Juveniles mammals are no longer fed by lactation and must find food for them selves, but they are not mature reproductively. Human beings are even more unusual and add a childhood stage after infancy and an adolescence stage after the juvenile stage. Children are no longer nursed by their mother and must be fed and cared for by other older individuals as the mother turns her investments toward a new pregnancy and infant. Adolescents are sexually maturing but not yet physically and emotionally mature enough to reproduce successfully. Both the body and the brain are growing and maturing during these pre-adult stages of life history. The human pattern of life history in both brain and body growth entails a large investment of energy and time by older members of the social group toward infants, children, juveniles, and adolescents. This is achieved via a new type of breeding strategy called biocultural reproduction. The evolution of human life history results in enhanced reproductive success for the individuals as well as technological, economic, and social success for our species. [Barry Bogin]