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Lab 2: Hominid AnatomySlide 2Lab MaterialsTerms to knowSlide 5Skeletal implications of bipedalismSlide 7Slide 8Slide 9Slide 10Slide 11PrognathismSlide 13Slide 14Slide 15Slide 16The brains develop in . . .Slide 18Cranial Capacity & Vaulted ForeheadSlide 20Slide 21Slide 22Slide 23Slide 24Slide 25Changes in dental arcadeSlide 27Crests and other muscle attachmentsSlide 29Slide 30Slide 31Slide 32Slide 33Adding to the confusion: Sexual DimporhismSlide 35Lab 2: Hominid AnatomyKey features to knowLab MaterialsSkeletal Changes In Human EvolutionThe earliest humans evolved in a parallel track with other primates. To understand the anatomical differences from an paleoanthropological perspective, you have to look at the fossils. You also have to understand some basic skeletal anatomy. This discussion section should help you recognize and understand major features and changes as apparent from the skulls. In section, you can handle skull casts of some of the non-human primates and some of the fossil hominids. You'll also have a simple classification exercise based on the skeletal features. The list of terms below is certainly not a complete list of all the anatomical comparisons, but you should know what they mean and where possible, you should look at each specimen so you have a better understanding. In class, you’ll look at parts 1-2 of the recent video series Ape Man which clearly shows the relationships and development of human evolution and anatomy. A book of the same title is also available. The terms listed below will all be explained in the class demonstrations and hands-on activities. Try to note what each term means and how the characteristics changed as our species evolved.Terms to knowLocomotion•Bipedal locomotionUpright postureStrideGreat toe The Hand•BrachiationOpposable thumbPrecision GripPower GripThe Skull•For an excellent web presentation and tutorial on the human (H.s.s.) skull, visit the Skull Module from the Department of Anthropology at CSU-Chico (http://www.csuchico.edu/anth/Module/skull.html. •Crests (saggital, occipital)Foreman magnumDental Arcade/Arch Y-5 Cusp pattern Supraorbital torusZygomatic archMandibleVaulted foreheadCranial capacityBinocular visionDiastema Try to understand the relationship between these elements in terms of the trends for evolutionary change.Erect postureShape of spinal columnRare, but possible, true or pseudo human tailsSkeletal implications of bipedalismLocation of foramen magnumBipedal LocomotionLaetoli FootprintsChimp and human footFemurs of upright walkers and ape Leg of apeQuadrupedal animals like apes, have femurs in which the ball joint, the part that joins the pelvis, sits directly over the inside of the knee. The angle subtended by the femur at the knee in quadrupedal walkers is less than that of bipedal walkers. Leg of Australopithecus afarensisThis diagram shows the femur with the same shape and structure as that of modern humans, but it is a little shorter. It subtends the same angle at the knee as that of a modern human and the inner bump of the knee joint is larger than the outer one. This shows that this hominin was also a bipedal walker. Leg of modern humanThis modern Homo sapiens bone shows the structure of the femur of an upright walker or bipedal animal. The ball joint, the part that joins the pelvis, sits directly over the outside of the knee. The angle subtended by the femur at the knee in bipedal walkers is greater than that of quadrupedal walkers. This results in the inner bump of the knee joint being longer than the outer bump.Skeletal implications of bipedalismPelvis, femur feetSkeletal implications of bipedalismKnock-kneed walkChimp vs. A. afarensisHuman Bipedalism—Balanced on the Edge of DisasterEadweard Muybridge (1830-1904) did early studies of human locomotionPrognathism“Muzzle” angles (prognathism) of ape and modern humanUnderstanding Physical Anthropology and Archaeology, 8th ed., p. 245Pongid Prognathism.(Line of greatest muscle force is shown in red.)Understanding Physical Anthropology and Archaeology, 8th ed., p. 245Satittal crests and temporal muscle orientations.Hominid compared to p ongid.(Line of greatest muscle force is shown in red.)Humankind Emerging, 7th ed., p. 389Human and Ape BrainsThe brains develop in . . .•size•complexity•the ratio of brain weight to overall body weightUnderstanding Physical Anthropology and Archaeology, 8th ed., p. 234Cranial CapacityCranial Capacity & Vaulted ForeheadHomo erectusAustralopithecus afarensisHomo (sapiens?) neandthalensisHomo sapiens sapiensTeeth / Dental ArcadeApes (and monkeys) still possess conical, dagger-like canines which project well beyond the surface of the opposite teeth.The gap is a diastema.Monkey & Ape CaninesTeeth of a male patas monkey.Understanding Physical Anthropology and Archaeology, 8th ed., p. 231plus-4Y-5Y-5Molar Cusp PatternsExample of early hominid fossil Y-5 cusp pattern molarsDental formulaeUnderstanding Physical Anthropology and Archaeology, 8th ed., p. 125Changes in dental arcade Modern Chimp Modern homo sapiens 100,000 ya to now Homo erectus 500,000 - 300,000 y Australopithecus africanus,2.8 - 2.3 mya Proconsul heseloni 19 - 17 myaThe Overall Pattern Is Toward Small Jaws and TeethCrests and other muscle attachmentsCrests and other muscle attachmentszygomatic archMandible and chewingMuscle attachmentsSome Important Skull FeaturesUnderstanding Physical Anthropology and Archaeology, 8th ed., p. 510Modern human cranium.For a nearly complete look at skulls, click on the image above for the Australian National Museum’s web site.Adding to the confusion:Sexual DimporhismHow much do we see in the fossil record?Be sure to look at Becoming Human, the Institute for Human Origins broadband documentary and web


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IUPUI A 103 - Lab 2 Hominid anatomy

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