ANTH 1013 Introduction to Biological Anthropology Summer 2014 Exam 3 Study Guide Remember this is a guide it is not comprehensive You should refer to your notes and text when reviewing this information making sure you understand how these terms and concepts are related to one another Simply memorizing terms will not be sufficient Exam 3 covers material from the following lectures Overview of Human Evolution What is a Hominin Piltdown Earliest Hominins Australopithecus and Paranthropus Origin of Genus Homo and Homo erectus Middle Pleistocene Hominins African Origin of Modern Humans The Peopling of the World Human Biological Variation Revisited Hominin Origins Hominoids Derived hominoid traits larger brain loss of tail long arms o o o o broad thorax Miocene Apes o locomotion Arboreal Quadrupedalism o Diet Terrestrial Quadrupedalism Suspension Fruigivory Folivory Seed Eating What happened to all the apes o Geographic distribution Africa and Asia everywhere for humans o Body size range 13 385 pounds or more o Activity pattern All diurnal o Locomotion Suspension knuckle walking bipedalism o Diet Fruit leaves insects meat seeds o 5 Genera Hylobates Pongo Gorilla Pan Homo o Global cooling restricted forested environments to the tropics This trend began in the mid Miocene 1 o In the more open habitats apes were unable to compete with the cercopithecoids Derived human traits small canines large brains o Obligately bipedal o o o broad dietary niche and tool use o extended time to maturity Great Ape and Humans diverge o 5 5 7 mya o What should we expect the earliest hominid to look like We would expect the earliest hominids to have looked very ape like the splitting of the chimp and human lineage has continued to evolve after it split from humans just as humans have evolved Chimp is not a living fossil Allopatric Speciation Derived features of hominids o o lack of gene flow leads to divergence accumulation of reproductive isolating mechanisms and eventual speciation In what order did human features evolve This tells us what makes a hominin adaptively speaking what set our lineage apart from the chimp lineage o How will we recognize the earliest hominin keeping in mind that there is no requirement for human features to have evolved simultaneously as a package Features related to bipedalism Foramen magnum orientation and postion Spine curvature to redistribute weight o Cervical and Lumbar Lordosis there are q2 lordotic posteriorly facing curves in the human spine and 1 kyphotic anteriorly facing curve in chimps and other apes the spine is stiff and straight with a single slightly kyphotic curve Valgus knee bicondylar angle Short broad ilium rotated into the sagittal plane o Pelvis and femur reorienting center of gravity and changing actions of muscles chimp pelvis narrow and tall ilium ilium lies in coronal plane into sagittal plane o o human pelvis broad and short ilium ilium rotates o hip stabilizing mechanism 2 lesser gluteal muscles are hip extensors in other primates but are hip abductors or stabilizers in humans In humans the iliac blade faces more laterally which changes the orientation of the hip muscles Divergent vs nondivergent hallux arches of the foot o Foot evenly distributing weight of entire body o o humans nondivergent hallux weight distributed through entire foot chimp divergent hallux weight distributed through entire foot into arches of the foot small canines o humans have very small non dimorphic canines o loss of canine honing extant nonhuman anthropoids have a functional complex that sharpens the canines and weaponizes them the first mandibular premolar is sectorial in chimps The human form is not large brains broad dietary niche and tool use extended time to maturity o humans incorporate substantial quantities of meat protein in their diet in some environments and use tools to acquire food Humans also have thick enamel on the post canine teeth o We break the human lifetime into a series of milestones that are referred to as life history o conception pregnancy 267 days infancy period up to weaning o o o when you are weaned you lose dependency on all mammals are dependent on their mothers for food until they are weaned from birth to weaning you are infant mother for nutrition You become a child cross culturally in humans natural period of o nursing is about 3 4 years o human milk is low in fat and protein frequent nursing o nursing suppresses ovulation lactational amenorrhea leads to average 4 year inter birth interval o even though you are weaned you are still not capable of fending for yourself when you are a child o humans provide food unusual 3 o o brain development and social learning is important during childhood community care important paternal care increases o o ends with the first eruption of you permanent teeth specifically your first permanent molar MI This happens around 6 years of age in living humans o end of childhood also occurs at approximately the same time as 95 of adult brain size is reached o as a juvenile you continue to grow in size and engage in lots of socialization and learning juvenility ends when the body is capable of reproduction i e sexual maturity You become an adolescent for females this milestone is menarche first menstruation for males this is the first ejaculation o as a juvenile secondary sexual characteristics begin to develop pubic hair breasts voice change etc o Though capable of being a parent as an adolescent the body does not cease growth until later o Between sexual maturity and physical maturity you are an adolescent cultural recognition of adulthood occurs when you are physically mature o o adulthood get a job work eat sleep raise kids get mocked by adolescents become bitter cynical bald etc o Senescence aging of organ systems menopause early senescence of female reproductive organs o o life history evolves like any other trait Human life history is different that that of a chimp our closest living relative chimp o human M1 4 Physical and Sexual maturity at 9 conception infant juvenile adult death solid foods perm teeth weaned M1 6 Sexual maturity 13 Physical maturity 18 conception infant child juvenile adolescent adult death solid foods weaned perm teeth How do we explain this constellation of features o big brains requires lots of energy calories and meat is a dense form o However apes don t have claws and sharp post canine teeth like a of calories carnivore so how did early humans consistently acquire meat 4 o use tools