HLTC23H3 Lecture Notes - Lecture 3: Primary Healthcare, Gender Inequality, Homo Habilis
Document Summary
Retention of juvenile characteristics in adult faces: retardation of somatic development. Same stages, but prolonged: results: larger body, brain, longer learning stage/lifespan, to explain why human brains are much larger than chimps although we have so much physiological similarity. Human species evolved because of introduction to new life stages into pattern, not heterochrony. Insertion of childhood for continuation of brain growth: some ancestor had some kind of beneficial mutation (adaptive advantage) and developed over time. Infancy prolonged, and then in homo habilis, childhood appeared and got longer along the species, homo erectus homo sapiens, etc. (shorter infancy and juvenile periods) Accounts for the speciation, the splitting and becoming of genus homo. After 400 cc of brain matter, actually need time to develop after birth (break open birth canal if came out fully developed: therefore, childhood came about as a stage to develop it. Childhood: long period of dependency in which brain growth is nurtured and fitness is increased.
