3 18 14 Chapter 10 What is a hominid What us different about humans Speech Cognition Culture Upright walking Non honing chewing apes HominiD the term used in 1993 for bipeds Us and our ancestors as distinguished from apes older outdated currently it includes HominiN contemporary term for bipeds N for NEW Most of the field accepts that out closest relatives are chimpanzees because of overwhelming evidence and some fossil records How did our common ancestor behave o Lived in Africa o Use hand me downs o Live in small scale societies outsiders Our common ancestor was probably characterized by o Open fission fusion communities a big group exists but breaks up into small groups then back together closed to o Some solitary foraging can be dangerous because of predators o Promiscuous mating is still in chimpanzees in humans it is all over the map Different cultures have different marriage and mating ideals Here in tally we shoot for monogamy but it is not the reality Serial monogamy is closer to reality o Female migration beneficial because of genetic variation 2011 dental data support this o Males may have been more bonded to each other than females the core of the group is made up of related males since they don t migrate out like females o Stalk and attack patrolling by males Our common ancestor probably looked like o 3 4 tall sexually dimorphic o Apelike body proportions long arms o Hair somewhat reduced thermoregulatory bare skin with a lot of sweat glands to cool off skin o Dark skin very HOT environment this is adaptive o Big front teeth fossil record evidence o Feet knees and pelvises starting to change bipedalism not fully striding but there are signs of the pelvis spinal chord and back in process of adapting for bipedalism o Small brain ape sized 300 350 cc o Walked like ducks waddled o Knuckle walked at times controversial Falk says yes Larson says no Very little evidence o Slept in trees Why did our ancestors get up and walk habitually on 2 legs o One of the biggest controversies in paleo politics o Freeing hands running after game Mary Leaky believes in persistence hunting hunting looking over tall grass efficient for staying cool Stanley Wheeler said that standing tall exposes a small region of your body to direct sunlight tool production sexual signaling 3 20 14 Non Honing Chewing o Honing versus apical wear o Shearing them versus grinding us o Male male aggression Why did hominids evolve o Owen Lovejoy s theory men want to help women because they want to have sex and impregnate them again o More food supports more infants which can lower IBI o Males develop bipedalism gather food for children o Females feed children can have more healthy offspring quicker o Suite of anatomies and behaviors co evolve Food provisioning Pair bonding Reduced canine size Cooperation Bipedalism Important pre ostalopithoscenes lucy is an ostalopithoscene o Sahalanthropis Tchadensis the oldest candidate in the known fossil record for a hominin was found in Tchad Central Africa Skull Discovered by Michelle Brunet The virtual endocast happens to show detail in the frontal lobes 2 sulci that have a configuration that you see in 4 endocasts of austrolophithecus o Orrorin Millennium Ancestor 6 mya in East Africa o Lucy Found in the Afar region in East Africa species Afarensis 3 4 mya 3 25 14 o Paranthropus IS NOT PART OF AUSTRALOPITHECUS only australopithecine robust side branch in relation to Who were the first hominids o Ardipithecus ramidus nicknamed Ardi 4 4 million years old Middle awash valley Ethiopia Africa forest Female 110 lb Claim bipedal ground clambered in trees Highly UNLIKELY to have been bipedal International team lead by T White and Y Haile Selassie modern humans Appear to have been an evolutionary dead end Morphology suggests they are not ancestral 2 TYPES 1 Aethiopicus o Ethiopia and Kenya Africa o 2 5 myo o woodlands and grasslands o 2 Boisei sagittal crest and large molars 3 Sediba south Africa malapa cave o o youngest date for australopethicus o nh1 juvenile male 11 13 y o o nh2 female o upward turned shoulders o ancestoral to homo o short pelvis long arms thinner mandible o The non robust autstralopithecines were the first hominids o First habitat Forested chads mosaic Hot times on the savanna Australopithecus anamenis o Ethiopia Tanzania and Kenya Africa o 1 2 2 3 myo o grasslands o o o but body size was pretty normal compared to other Australopithecus sagittal crest theyre called robust because of their thick skulls o Kenya and Ethiopia Africa woodland o 4 million years old o M Leakey and T Whitte o Anatomies bipedal based on the shin bone and nonhoning canine o Australopithecus afarensis includes LUCY 3 2 million years old little baby endocast found in similar area cranial morphology may not have been as advanced big male also found these discoveries underscore the fact that this was a highly sexually dimorphic species M Leakey uncovered trail of footsteps in Laetoli Tanzania 3 6 mya footprints had round heel toes double arch Significant because it showed although brain size was not advanced bipedalism had already developed The feet came first o Kenyanthropus Kenya Africa 3 5 myo o Garhi Ethiopia Africa 2 5 myo large teeth long legs stone tools The First Tool Makers o Oldowan stone tools 2 6 myo o Australopithecus first stone tool makers not Homo o Oldest cut marks on bone 3 4 myo o Tools looked like rocks sometimes called pebble tools South African Australopithecines o Australopithecus africanus 2 3 mya small non honing canines large premolars and molars bipedal o paranthropus robustus 1 5 2 mya small non honing canines very large premolars and molars bipedal o Australopithecus sediba 1 9 myo malapa cave forest and grassland anatomy small brain small teeth human like hands and pelvis mosaic foot Chapter 11 The Origins and Evolution of Early Homo 1891 Eugene Dubois 1858 1940 o Dutch physician and anatomist medical scientist o Homo erectus pithecanthropus erectus ape man o First found a skull cap the next year he found a femur o Known now though to be 1 8 mya 27kyo o Trinil fossils pathology on femur myositis ossificans traumatica found in the solo river o Scientists rejected fossil A number of established scientists suggested his discovery was a microcephalic idiot rather than a missing link that was transitional between apes and humans o Some argues that the skullcap was from an aberrant ape a giant gibbon o Became depressed and eccentric He didn t want to show anyone his