reconstructions by John Gurche for National Geographic3/29/18 The Genus Homo & the 1stOut of AfricaD3444D2700D228212Practicalities• Midterm #2 (4/5/18) is a week from today, covering lectures through today and this week’s lab (Lab #9) but not Lab 10.• Lab 10 will be held next week 4/2-4/5.• No lab between 4/9 and 4/12.3Topics for Today• Homo habilis and the Cerebral Rubicon• Who made the Oldowan?• Some sample Midterm 2 questions• The Questions of “Early Homo” – One or Two species?– Homo or the last examples of Australopithecus?• The Site of Dmanisi and Hypotheses for the 1stOut of Africa range expansion for homininsWhat does it mean to be human?• Large brain• Obligate biped• Complex tool use• Fully opposable thumb• Reduced dentition• Greatly reduced canines• Reduced prognathism• Gracile morphology• Reduced sexual dimorphism• Reduction in body hair• Increased number of sweat glands• Neoteny/slowed maturation• Complex culture• Language^4Leakey, Tobias, & Napier (Nature, 1964)• Extend the range of the genus Homo to include brain sizes of 600c.c.• Homo habilis (type-specimen = Olduvai Hominin 7)• Type and paratype mostly juveniles or fragments• Stone tools• 1.8-1.6 Ma5700c.c. (Weidenreich)800c.c. (Vallois)750c.c. (Keith)Australopithecus & ParanthropusHomo350-550c.c.1050-1600c.c.6Early Homo locomotor adaptations: a slightly better biped than the AustralopithsOH 8 footOH 62OH7 typeMore derived, bipedal foot than A. africanusDentition shows chimp-like growth ratePossibly still has arboreal intermembralindex but data uncertain7Figure 01.11The Unusual Suspects8Fingers: Robusticity of finger bones indicates presence/absence of power grip9Fingers indicating tool use1011Paranthropus robustus & Homo habilis finger tips12Who made the Oldowan?Paranthropus?• Large apical tufts with precision gripping hand, unlike apes or A. afarensis.• Same brain size as some early Homo fossils.• More frequent fossils between 2.5-1.9 mya.• Meat cannot drive their C4dietary signature.• Tiny anterior dentition may point to stone tool processing of foods before they go into the mouthEarly Homo?• Precision grip• Larger brain to body size ratio.• Reduced anterior dentition• Current dates between 2.4 & 1.6 mya.Figure 01.11And the Lomekwian? The Even More Unusual Suspects13Current Hominin Associations?14The Lomekwian(Industry?)at 3.3 mya,Possibly A. afarensisThe OldowanIndustryat 2.6 mya,Possibly P. boisei& H. habilisChimpanzees & capuchin monkeys todayShea 2017, Stone Tools in Human Evolution, Cambridge University Press.For exams, focus on the differences between the major letter categories (e.g. B vs. E) among the Flintknapping Modes A-I, rather than the differences between Arabic sub-numbers, e.g., “D1 vs. D2”)15The lecture content for Midterm #2 covers up to (and including) this slide.Midterm 2 Sample questions:ALA 17a Use ChimeIn.cla.umn.edu orText 24798 plus your answer to to 15037706789 to answer via SMS.17a. Based on the discovery of multiple bones showing bipedality from multiple individuals, which genus is currently interpreted to be the first certain biped?a. Orrorinb. Sahelanthropusc. Ardipithecusd. Australopithecuse. Paranthropus1617b. Imagine you are a paleoanthropologist working at a site believed to be older than 300,000 years old in East Africa. There is partially fossilized bone in the layer with the hominin. There is also a volcanic ash layer (tuff) covering the layer with the hominin remains. Which of the following radiometric techniques would be the best choice to date the material?a. Carbon-14b. Potassium-Argonc. Uranium series datingd. Thermoluminescencee. Paleomagnitism17Midterm 2 Sample questions:ALA 17b Use ChimeIn.cla.umn.edu or Text 24797 plus your answer to 15037706789 to answer via SMS.17c. True or False: A valgus knee with a bicondylarangle is seen in habitual quadrupeds.a. Trueb. False18Midterm 2 Sample questions:ALA 17c. Use ChimeIn.cla.umn.edu orText 24799 plus your answer to 15037706789 to answer via SMS.Early HomoER 1470752 cc brain19Early HomoER 1470752 cc brain20Figure 11.3221Early HomoER 1813509 cc brain22Figure 11.34• Early Homo dates between 2.4 & 1.6 mya.• ER 1470 has Australopith face, with molars the size of africanus, but with bigger brain.• ER 1813 has more derived (more modern) traits of smaller face & smaller teeth, but also smaller brain.23The Debate over Early Homo• Lump Hypothesis: Males with Australopith face and larger brain, females with more derived (H. erectus) small face but smaller brains.• Split Hypothesis: too much dimorphism (Bernard Wood)– Homo habilis (i.e., OH7, OH 12, OH 16, OH 24, KNM-ER1813, KNM-ER1805) – Homo rudolphensis (Lake Turkana Homo) (KNM-ER1470, 1590, 3732, & 1802)24Remember:Evolution is a(n) _____________,not a(n) ________________.2526Mosaic evolution: different traits evolve at different rates26Australopiths: mosaic evolution of different ways to be a biped and different ways to chew foodEarly Homo: mosaic evolution of different ways to house a larger brain in the skullType fossil for H. habilis is OH 7, a small fossil like ER 1813. 27Homo habilisHomo rudolphensisFor splitters such as Bernard Wood, early Homofalls within the genus Australopithecus based on their shared “adaptive grade” (way of life).28A. habilisA. rudolphensisEncephalization Quotient:how big is the brain relative to what you would expect for the body size?29P. boiseiP. robustus30Orrorin tugenensisModern humanAustralopithecus anamensisAustralopithecus afarensisAustralopithecus africanusParanthropus boiseiParanthropus robustusParanthropus aethiopicusA. garhiOur current view of early human evolutionHomo habilisHomo rudolfensisA. sediba1stOut of Africa, best date currently Stone tools at 1.85 myaHominin fossils at 1.78 myaDmanisi, Georgia31Martha Tappen of U of M at Dmanisi, Georgia32reconstructions by John Gurche for National GeographicFirst finds from Dmanisi, GeorgiaD3444D2700D228233Recently expanded Dmanisi Population, Republic of Georgia34The newest skull3536A mosaic of cranial traits within one population37Post-cranial bones from 4 individualsModern HumanDmanisiRange ExpansionMain Routes Out of AfricaStraits of GibraltarSinai PeninsulaBab-el-Mandeb StraitAfricanapesEarly homininsHypotheses for Hominin Range Expansion: Why leave Africa?• Technological change: evolution of the Acheuleantradition out of the Oldowan?•
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