Early Hominins and Hominids
Early Hominins and Hominids ANTH 1102
Popular in Introduction to Anthropology
verified elite notetaker
Popular in anthropology, evolution, sphr
verified elite notetaker
This 4 page Class Notes was uploaded by Carina Sauter on Sunday February 14, 2016. The Class Notes belongs to ANTH 1102 at University of Georgia taught by Dr. Birch in Winter 2016. Since its upload, it has received 31 views. For similar materials see Introduction to Anthropology in anthropology, evolution, sphr at University of Georgia.
Reviews for Early Hominins and Hominids
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/14/16
Early Hominids and Hominins: Humanity’s Family Tree • Between 5 and 8 million years ago our ancestors diverged genetically and behaviorally from those of the other African apes o Great Rift Valley, Africa § Most of our fossils and educational material are found here § Fault opened up • Hominin/hominid split • Sahelanthropus tchadensis o Discovered in Chad, 2001 o Approximately 7 million years old o Unclear whether it lived before or after human–chimp divergence (if it’s a hominid or a hominin) • Orrorin tugensis o Discovered in Kenya, 2001 o 13 fossils of 5 individuals o Approximately 6 million years old o Shares characterisitcs with miocene apes and later hominids o Unclear if it lived before or after human-chimp divergence (if it’s a hominid or hominin) § Fuzzy area of where hominin and hominid lives diverge § All hominins are hominids, not all hominids are hominins • Hominid: the taxonomic family that includes humans, African apes and our immediate ancestors • Hominin: the human line after our split from chimpanzees o No other living ancestors except homo sapiens • Ardipithecus ramidus o Approximately 4.4 million years old o Discovered recently – the most famous individual in 2010 o “Ardi” o pelvis is transitional between arboreal and terrestrial o lived in a humid woodland habitat § we may be able to tell what year he is from because of the pollen found in the flowers that were buried with him – or could just be a lot of pollen in area o shift to bipedal existence and two legs on land § related to drying out of African climate – lived before drying out • Kenyanthropus platyops o Discovered in Kenya, 1999 o Approximately 3.5 million years old o Nearly complete skull and partial jawbone o Raised the possibility that two hominin lineages existed as far back as 3.5 million years ago o “flat faced man of Kenya” • Australopithecines o Two indisputable facts: § Bipedal with some retention of adaptation to arboreal life § Evolution of erect bipedal position long before acquiring highly enlarged brain • The anatomy of bipedalism o Position of foramen magnum is more forward in bipedal § Making sense of gravity shift o Wider, shorter pelvis o Angle of femur: “kneeing-in” of thigh bones (femoral) o Stable arched foot o No opposable big toe o Shorter toes • Early Australopithecines o Australopithecine anamensis § 3.9-4.2 million years ago § likely bipedal but still partially adapted to climbing in trees § very fragmentary fossil record § pelvis and leg like later human ancestors but still had larger forelimbs § bones show they were physically strong § similar hands to humans o Australopithecine afarensis § 3.8-3.0 million years ago § ape-like crania § bipedal: human-like postcranial skeleton § likely evolved from anamensis § “Lucy” • female discovered in 1970’s § Sexual dimorphism § Teeth and diet • Large molars compared to humans o Teeth adapted to accommodate heavy chewing of coarse, fibrous vegetation of the savanna o Case of many hominin ancestors until homo erectus • Laetoli Footprints, Tanzania o 3.6 million years old o footprints in volcanic ash o evidence of human-like bipedal locomotion of Australopithecines o adult (dad?), smaller adult (mom?), smaller child (child?) • Robust and Gracile Australopithecines o Between 3 mya and 2 mya we moved to r. and g. australopithecines § Both have projection at bottom of face o Gracile Australopithecines § Apelike skull morphology § Likely our direct ancestor § Australopithecine africanus • 3-2 mya? • erect bipeds about 1-1.5 meters in stature • apelike skull • teeth for chewing food in a hominin fashion • lineage split into two groups, one of which evolved into the genus homo § Australopithecine garhi • 2.5 mya • garhi = surprise • Fragmentary cranial fossil • Evolutionary link between Australopithecus and Homo? Or a side branch? • Longer femur (compared to other Australopithecus specimens) = longer strides? • Found with stone tools and animal bones with cut marks o Potentially producing stone tools, scavenging and butchering animals o Important because we thought homo-habilis were the first to use tools o Robust Australopithecines (paranthropus) § Australopithecine boisei, Australopithecine robustus § More strongly built § Sagittal crest for chewing muscles • Strong muscle attachment for jaw o Chewing machines – adapted to very arid environment o Dense crania, huge mandible, massive teeth § Tough, unprocessed plant foods § Thick bones for their size, with prominent muscle markings • Oldowan Tools o Approximately 2.6 mya o Olduvai Gorge: “Type-site” for Oldowan tools § Used to be a lake § Richest location of all of Africa for human ancestry, stone tools and archeological sites because of the rich soil o Broken to create sharp edges, effective for cutting and scraping o Microscopic wear patters show tool use for cutting meat, grasses and wood o Stones fit well in our hands o Cut meat § Important addition of protein to diet for brain development o Biocultural development § Intentionally created stone tools o Early stone tools and culture § Evidence that it was intentional and forethought § Early tool makers knew: • What material to select • The intended function of the object • How to repeatedly produce a similar product • How to pass this knowledge on to others § Based on assumption that breaking of flakes will give you a tool used for a specific purpose § Forethought: what material should you select? § 2.6 mya: knew what material to select and knew what function/purpose that tool had o Early stone tools and meat § Dentition of Australopithecus and homo is poorly suited for processing carcasses § Sharp tools for butchering were needed § Archaeological remains suggest meat was first acquired by scavenging, not hunting • Find more dead animals in isolation from this period – not whole body o Carved off chunks and brought to a safe place to eat o Could also find our own bodies § Other animals were above us on the food chain § Stone tools allowed the addition of meat to diet on a frequent basis § Increase in brain size correlated with appearance of mean in hominin diet • Brain size nearly doubles from Australopithecus to homo erectus – more active brains • Could not get this protein earlier – meat is more energy dense than plants o More calories per gram o Consuming more than twice the amount of calories
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'