fossil hominins from ardipithecus to homo
DESCRIPTION
Human evolutionTRANSCRIPT
Fossil Hominins: General Fossil Hominins: General Trends Toward Trends Toward Homo SapiensHomo Sapiens
Large bulbous craniumLarge bulbous cranium Short face compared to apeShort face compared to ape Vertical carriage of headVertical carriage of head Hands and Forelimbs Adapted to Tool Hands and Forelimbs Adapted to Tool
Making and UseMaking and Use Bipedal Structure of Postcranial SkeletonBipedal Structure of Postcranial Skeleton
Model of Human Evolution: Model of Human Evolution: Ardipithicus to AustralopithecinesArdipithicus to Australopithecines
Ardipithecus ramidus Ardipithecus ramidus to to AustralopithecinesAustralopithecines
Australopithecus afarensis to A. Australopithecus afarensis to A. africanusafricanus: Gracile Australopithecines: Gracile Australopithecines
Paranthropus robustus and boisei:Paranthropus robustus and boisei: Robust Australopithecines—Dead end?Robust Australopithecines—Dead end?
A. africanus A. africanus to to Homo habilisHomo habilis: Rise of : Rise of tool manufacture?tool manufacture?
Model of Human Evolution: Model of Human Evolution: Homo habilisHomo habilis to Sapients to Sapients
H. habilisH. habilis to to H. erectus: H. erectus: Global spread; Global spread; increased tool assemblageincreased tool assemblage
H. erectus H. erectus to to H. sapiens:H. sapiens: Tool Tool specialization and population explosionspecialization and population explosion
H. neanderthalensis: Dead end?H. neanderthalensis: Dead end? Homo sapiens: Homo sapiens: (Future) End of the (Future) End of the
Line?Line?
Fossil Trends: Encephalization Fossil Trends: Encephalization (Cranial Capacity Increase)(Cranial Capacity Increase)
Ardipithecus ramidus: Ardipithecus ramidus: ca. 300-350 cc. ca. 300-350 cc. Australopithecus. afarensis:Australopithecus. afarensis: 390-500 cc; 390-500 cc;
av. 440 ccav. 440 cc A. africanus: A. africanus: 435-530 cc; av. 450 cc435-530 cc; av. 450 cc A./P robustus: A./P robustus: 520 cc, one specimen520 cc, one specimen A.P. boisei: A.P. boisei: 500-530 cc; av. 515 cc.500-530 cc; av. 515 cc.
Ardipithecus ramidis: The “Rooted Ardipithecus ramidis: The “Rooted Ground Floor Ape”Ground Floor Ape”
Ardi: “Ground Floor” (Afar)Ardi: “Ground Floor” (Afar) Rama: “Root”Rama: “Root” Pithecus: “ape”Pithecus: “ape” Date: 4.4 million years Date: 4.4 million years
ago (mya)ago (mya) Location: Middle Awash Location: Middle Awash
River Valley, NE EthiopiaRiver Valley, NE Ethiopia Size: 120 cm (4 ft.)Size: 120 cm (4 ft.) Weight (est.) 50 kg (110 Weight (est.) 50 kg (110
lb.); heavier than Lucy lb.); heavier than Lucy
Ardipithecus ramidus: Ardipithecus ramidus: Reconstructed FeaturesReconstructed Features
Cranial capacity: 300-350 cc.Cranial capacity: 300-350 cc. Teeth: apelike with reduced Teeth: apelike with reduced
canines; probably omnivore canines; probably omnivore and/or fruit-eaterand/or fruit-eater
Significant prognathism Significant prognathism (projection of lower face)(projection of lower face)
Feet: opposable toe with no Feet: opposable toe with no archesarches
Quadrupedal in treesQuadrupedal in trees Faculative biped on the ground: Faculative biped on the ground:
could walk short distances.could walk short distances.
Homo habilis to Homo sapiensHomo habilis to Homo sapiens
H. habilis: H. habilis: 500-800 cc; av. 680 cc.500-800 cc; av. 680 cc. H. erectus: H. erectus: 750-1250 cc; av. 1000 cc750-1250 cc; av. 1000 cc Neanderthal: 1300-1750 cc. av: 1450Neanderthal: 1300-1750 cc. av: 1450 H. (s.) sapiens: H. (s.) sapiens: 900-2350 cc. av. 1400900-2350 cc. av. 1400
Fossil Trends: Forelimbs and Fossil Trends: Forelimbs and HandsHands
Shortened forelimbShortened forelimb Hands (manipulation, not locomotion)Hands (manipulation, not locomotion) Enlarged thumbEnlarged thumb Straight, noncurved fingerStraight, noncurved finger Enhanced finger sensitivityEnhanced finger sensitivity
Fossil Hominins: General Fossil Hominins: General Trends--BipedalismTrends--Bipedalism
S-shaped vertebrae (backbone)S-shaped vertebrae (backbone) Short, wide, bowl-shaped pelvisShort, wide, bowl-shaped pelvis Femoral head (ball of femur at pelvis) Femoral head (ball of femur at pelvis)
angled and strengthenedangled and strengthened Lengthened hindlimbLengthened hindlimb Angle of knee: femur “slopes” to pelvisAngle of knee: femur “slopes” to pelvis Platform (arched) structure of footPlatform (arched) structure of foot Nonopposable big toe; toes not curved Nonopposable big toe; toes not curved
Lucy (Lucy (Australopithecus afarensisAustralopithecus afarensis) ) and Us (Homo sapiens)and Us (Homo sapiens)
Note the Following:Note the Following: Shorter (3’6”)Shorter (3’6”) Longer armsLonger arms Curved fingersCurved fingers Shorter lower legsShorter lower legs Greater prognathismGreater prognathism Sloped foreheadSloped forehead Smaller cranial capacitySmaller cranial capacity What are the Similarities?What are the Similarities? Hint: it’s all related to bipedalismHint: it’s all related to bipedalism
Bipedalism: A. afarensis and H. Bipedalism: A. afarensis and H. sapiens compared, Fine Pointssapiens compared, Fine Points
When We Became Bipedal When We Became Bipedal (According to Gary Larson)(According to Gary Larson)
““Hey! Look! No Hey! Look! No hands!”hands!”
(Does he look like (Does he look like Lucy to you. . .?)Lucy to you. . .?)
Gracile and Robust Gracile and Robust AustralopithecinesAustralopithecines
For For A. africanusA. africanus (top), note: (top), note: Somewhat rounder skullSomewhat rounder skull No Sagittal crestNo Sagittal crest Prognathous jawPrognathous jaw For Paranthropus boisei, note:For Paranthropus boisei, note: Sagittal crest (ate a lot of veggies)Sagittal crest (ate a lot of veggies) Massive lower jaw (mandible)Massive lower jaw (mandible) Flatter faceFlatter face Massive cheek bones (zygomatic Massive cheek bones (zygomatic
arch)arch)
Summary of AustralopithecinesSummary of Australopithecines
Cranial capacity increased marginallyCranial capacity increased marginally All australopithecines hadAll australopithecines had Sloping foreheadsSloping foreheads Prominent brow ridgesProminent brow ridges Prognathous lower face and jawsPrognathous lower face and jaws Bipedal postcranial skeletonsBipedal postcranial skeletons Robust forms probably were dead endsRobust forms probably were dead ends Graciles likely evolved toward Graciles likely evolved toward HomoHomo. .
Australopithecus and Homo Australopithecus and Homo Compared—Frontal ViewCompared—Frontal View
Left: Left: A. africanusA. africanus Right: Right: H. habilisH. habilis Note:Note: Different Cranial Different Cranial
CapacitiesCapacities Brow Ridge SizeBrow Ridge Size
Australopithecus and Homo Australopithecus and Homo Compared—Side ViewCompared—Side View
Top: A. africanusTop: A. africanus Bottom: H. habilisBottom: H. habilis Compare:Compare: Mass of JawsMass of Jaws Size of CraniaSize of Crania PrognathismPrognathism
Postorbital ConstrictionPostorbital Constriction
Left: Homo erectusLeft: Homo erectus Right: Australopithecus Right: Australopithecus
africanusafricanus Note the narrower Note the narrower
constriction of A. constriction of A. africanus’s postorbital africanus’s postorbital constriction than that constriction than that of H. erectusof H. erectus
Homo habilis: Homo habilis: The First Known The First Known ToolmakerToolmaker Note the following:Note the following: Face is much flatterFace is much flatter Reduced brow ridge (supraorbital Reduced brow ridge (supraorbital
torus) torus) Larger cranial capacity (680 cc.)Larger cranial capacity (680 cc.) Toolmaking TechniqueToolmaking Technique HammerstoneHammerstone used to strike used to strike A A core core (lump of stone) to knap(lump of stone) to knap A A Flake Flake (stone chip)(stone chip) Note: Note: Stone has to be crystalline Stone has to be crystalline
(so it will fracture predictably)(so it will fracture predictably)
Australopithecines and Homo Australopithecines and Homo Compared ICompared I
Cranial capacityCranial capacity Australopithecines: 400-530 ccAustralopithecines: 400-530 cc Homo: 500-2300Homo: 500-2300 Maximum braincase widthMaximum braincase width Australopithecines: low on skullAustralopithecines: low on skull Homo: near topHomo: near top Postorbital constrictionPostorbital constriction
Australopithecines: markedAustralopithecines: markedHomo: moderate to slight Homo: moderate to slight
Australopithecines and Homo Australopithecines and Homo Compared IICompared II
Supraorbital torus (brow ridge)Supraorbital torus (brow ridge) Australopithecines: large to moderateAustralopithecines: large to moderate Homo: large to slightHomo: large to slight Zygomatic archZygomatic arch Australopithecines: large, flaringAustralopithecines: large, flaring Homo: small, not flaringHomo: small, not flaring
Australopithecines and Homo Australopithecines and Homo Compared IIICompared III
Facial size relative to brain caseFacial size relative to brain case Australopithecines: largeAustralopithecines: large Homo: smallHomo: small JawJaw A: Massive and prognathic; no chinA: Massive and prognathic; no chin H: Not massiveH: Not massive Prognathism slight to nonexistent;Prognathism slight to nonexistent; Chin present in sapientsChin present in sapients Molars and premolarsMolars and premolars Australopithecines: large; Australopithecines: large; afarensisafarensis with diastema with diastema Homo: smallHomo: small
Australopithecines and Homo Australopithecines and Homo Habilis Compared: SkullsHabilis Compared: Skulls
General trendsGeneral trends Encephalization: Cranial capacity increasesEncephalization: Cranial capacity increases Dentition: Cheek teeth are reducedDentition: Cheek teeth are reduced Sagittal Crest (where chewing muscles Sagittal Crest (where chewing muscles
attach)attach) A./P. robustus and boisei: A./P. robustus and boisei: pronouncedpronounced A. africanus: A. africanus: sagittal keel or absentsagittal keel or absent H. habilis: H. habilis: absentabsent
Australopithecines and Homo Australopithecines and Homo Habilis Compared: Skull/FaceHabilis Compared: Skull/Face
BraincaseBraincase A./P. robustus/boisei: A./P. robustus/boisei: less roundedless rounded A. africanus: A. africanus: more roundedmore rounded H. habilis:H. habilis: most rounded of the three most rounded of the three Zygomatic archZygomatic arch A./P. robustus/boisei: very pronouncedA./P. robustus/boisei: very pronounced A. africanus: A. africanus: less pronouncedless pronounced H. habilis: H. habilis: far less pronounced than the far less pronounced than the
australopithecinesaustralopithecines
Homo habilis: Hands and FeetHomo habilis: Hands and Feet
HandsHands Curvature of finger bones are apelike, indicate Curvature of finger bones are apelike, indicate
powerful grip (arboreal)powerful grip (arboreal) Indications of greater manipulative skillIndications of greater manipulative skill Larger blood supply to hand than earlier Larger blood supply to hand than earlier
hominidshominids Evidence of greater nerve supplyEvidence of greater nerve supply Feet: existing fragments indicate modern form:Feet: existing fragments indicate modern form: Remains lacked toesRemains lacked toes
Tool Traditions: Oldowan Tool Traditions: Oldowan
Named after Olduvai GorgeNamed after Olduvai Gorge Among the finds at Olduvai:Among the finds at Olduvai: Side chopper, a core toolSide chopper, a core tool Several flake tools, includingSeveral flake tools, including End scraperEnd scraper Side scraperSide scraper BurinBurin Utilized flakes of unknown functionUtilized flakes of unknown function Belongs to Lower Paleolithic Belongs to Lower Paleolithic
Manufacturing ChoppersManufacturing Choppers
ProcedureProcedure Knapper strikes a spherical piece of stoneKnapper strikes a spherical piece of stone Flake falls off opposite sideFlake falls off opposite side Tool flipped over and procedure repeatedTool flipped over and procedure repeated Several blows create a cutting edgeSeveral blows create a cutting edge Requirements reflect IntelligenceRequirements reflect Intelligence Planning and foreknowledge of designPlanning and foreknowledge of design Knowledge of breakage pattern of rockKnowledge of breakage pattern of rock Hand-eye coordinationHand-eye coordination
Oldowan TraditionOldowan Tradition
End chopperEnd chopper Heavy duty scraperHeavy duty scraper Flake scraperFlake scraper Spheroid Spheroid
HammerstoneHammerstone ChopperChopper Horn core tool or Horn core tool or
diggerdigger
Homo habilis and Homo erectusHomo habilis and Homo erectus
Compared to Compared to H. habilis, H erectus H. habilis, H erectus had:had: Larger brain (1000 cc vs 680 cc average)Larger brain (1000 cc vs 680 cc average) Forehead flatter, less slopingForehead flatter, less sloping More rounded occipital torusMore rounded occipital torus endocasts indicate hemispheric endocasts indicate hemispheric
asymmetryasymmetry Homo erectus and Homo sapiensHomo erectus and Homo sapiens
Homo erectusHomo erectus or or ergasterergaster
Note:Note: Apelike but larger craniumApelike but larger cranium Postcranial SkeletonPostcranial Skeleton Vertebrae: S ShapedVertebrae: S Shaped Ribcage: Not funnel shaped, now Ribcage: Not funnel shaped, now
like ourslike ours Pelvis: Bowl shapedPelvis: Bowl shaped Angle of ThighboneAngle of Thighbone
Homo erectus and Homo Homo erectus and Homo Sapiens: Cranium (Braincase)Sapiens: Cranium (Braincase)
Forehead (Frontal)Forehead (Frontal) H. erectus: H. erectus: sloping; low and flatsloping; low and flat H. sapiens: H. sapiens: vertical, indicating frontal lobevertical, indicating frontal lobe Supraorbital torus (brow ridge)Supraorbital torus (brow ridge) H. erectus: H. erectus: prominent--extending as a barprominent--extending as a bar H. sapiens: H. sapiens: slight or absentslight or absent Occipital torus:Occipital torus: H. erectus: H. erectus: presentpresent H. sapiens: H. sapiens: slight or absentslight or absent
Homo erectus and Homo Homo erectus and Homo sapiens: Cranium and Facesapiens: Cranium and Face
Sagittal keelSagittal keel H. erectus: H. erectus: present; vestige of crest?present; vestige of crest? H. sapiens: H. sapiens: slight or absentslight or absent Postorbital constrictionPostorbital constriction H. erectus: H. erectus: pronouncedpronounced H. sapiens: H. sapiens: slight or nonexistentslight or nonexistent
Homo erectus and Homo Homo erectus and Homo sapiens: Facial Skeletonsapiens: Facial Skeleton
Facial skeletionFacial skeletion H. erectus: H. erectus: Relatively large, with large Relatively large, with large
orbits and nasal openingorbits and nasal opening H. sapiens: H. sapiens: Relatively small, with small Relatively small, with small
orbits and nasal openingorbits and nasal opening Prognathism (jutting jaw)Prognathism (jutting jaw) H. erectus: H. erectus: PronouncedPronounced H. sapiens: H. sapiens: minimal or nonexistentminimal or nonexistent
Homo erectusHomo erectus and and Homo sapiensHomo sapiens skullsskulls
Compare:Compare: Brow ridges (supraorbital tori)Brow ridges (supraorbital tori) PrognathismPrognathism Constriction behind eye sockets (postorbital constriction)Constriction behind eye sockets (postorbital constriction) Presence versus absence of chinPresence versus absence of chin
Tool Traditions: AcheuleanTool Traditions: Acheulean
Named after St. AcheulNamed after St. Acheul Characteristics of Acheulean handaxeCharacteristics of Acheulean handaxe Bifacial: both sides knappedBifacial: both sides knapped Symmetrical in breadthSymmetrical in breadth Shaped to a point on one endShaped to a point on one end The edge is thin and sharpThe edge is thin and sharp Broad end is curved, but edge is still sharpBroad end is curved, but edge is still sharp Part of Lower Paleolithic Part of Lower Paleolithic
Acheulean Axe as “Swiss Army Acheulean Axe as “Swiss Army Knife”; Abbevillean variationKnife”; Abbevillean variation
Swiss Army Rock?Swiss Army Rock? Sharp tip: used for piercingSharp tip: used for piercing Thin edge: used for cutting (hide or meat off Thin edge: used for cutting (hide or meat off
bone)bone) Broad end: used for chopping or scrapingBroad end: used for chopping or scraping Abbevillean Variation:Abbevillean Variation: Bifacial, like the AcheuleanBifacial, like the Acheulean Not quite so symmetricalNot quite so symmetrical Olduvai specimen: transitional type?Olduvai specimen: transitional type?
Manufacturing Acheulean Manufacturing Acheulean HandaxesHandaxes
A demanding taskA demanding task Symmetrical, finely shapedSymmetrical, finely shaped Dozens of flakes removed, from 25 to 75Dozens of flakes removed, from 25 to 75 Each flake blow must be precisely positionedEach flake blow must be precisely positioned Core must be turned over again and againCore must be turned over again and again to maintain symmetryto maintain symmetry to keep edge straightto keep edge straight All the exterior rind (All the exterior rind (cortexcortex) was removed ) was removed
Abbevillian and Acheulean Abbevillian and Acheulean HandaxesHandaxes
Left: Abbevillian. Note asymmetry, rough retouchLeft: Abbevillian. Note asymmetry, rough retouch Right: Acheulean. Note symmetry, fine retouchRight: Acheulean. Note symmetry, fine retouch
Homo heidelbergensisHomo heidelbergensis or or “Archaic” “Archaic” Homo sapiensHomo sapiens
Left: Skull. Note heavy brow ridge, prognathismLeft: Skull. Note heavy brow ridge, prognathism Right: Mandible. Note arc-like dental arcade, absence Right: Mandible. Note arc-like dental arcade, absence
of diastema, absence of chin of diastema, absence of chin
Manufacturing Levallois Cores Manufacturing Levallois Cores and Flakesand Flakes
KnappersKnappers Draw outline of flake on stone moduleDraw outline of flake on stone module Strikes flake of desired shapeStrikes flake of desired shape Requires knowledge of breakage pattern of Requires knowledge of breakage pattern of
rockrock Prepares rock beforehand to control how rock Prepares rock beforehand to control how rock
breaks when struckbreaks when struck Ensure right shape (e.g. cutting, perforation, Ensure right shape (e.g. cutting, perforation,
piercing) is struckpiercing) is struck
Homo neanderthalensisHomo neanderthalensis: Skeleton: Skeleton
Left:Left: Homo Homo neanderthalensisneanderthalensis
RightRight: : Homo sapiensHomo sapiens CompareCompare Relative thickness of Relative thickness of
bonesbones Breadth of ribcagesBreadth of ribcages Size of skullsSize of skulls
Homo neanderthalensis: Homo neanderthalensis: CraniumCranium
Left:Left: H. neanderthalensisH. neanderthalensis: note larger cranial size, occipital bun, : note larger cranial size, occipital bun, prognathism, brow ridgeprognathism, brow ridge
RightRight: : H. sapiensH. sapiens: Note rounded cranium, presence of chin, absence of : Note rounded cranium, presence of chin, absence of prognathism and brow ridgeprognathism and brow ridge
Mousterian TraditionMousterian Tradition
Positively identified with NeanderhalsPositively identified with Neanderhals Le Moustier, France is a Neanderthal siteLe Moustier, France is a Neanderthal site Belongs to Belongs to Middle PaleolithicMiddle Paleolithic More sophisticated than Oldowan or More sophisticated than Oldowan or
Acheulean, both Acheulean, both Lower PaleolithicLower Paleolithic
Mousterian Tool AssemblageMousterian Tool Assemblage
Sample includes Scrapers, Points, and Sample includes Scrapers, Points, and HandaxesHandaxes
Upper Paleolithic: The Great Upper Paleolithic: The Great Leap Forward?Leap Forward?
Probably begins about 50,000 BPProbably begins about 50,000 BP Primary AttributesPrimary Attributes Shift from flake tools to bladesShift from flake tools to blades Subsistence on greater range of animal Subsistence on greater range of animal
and plant speciesand plant species Larger sitesLarger sites Increase of bone, antler, ivory, shell, and Increase of bone, antler, ivory, shell, and
other materials for toolsother materials for tools
Upper Paleolithic: Associated Upper Paleolithic: Associated AttributesAttributes
Associated AttributesAssociated Attributes Greater use of “imported” goods: Greater use of “imported” goods: raw materials obtainable only fromraw materials obtainable only from great distances from inhabited sitesgreat distances from inhabited sites which suggests tradewhich suggests trade More elaborate burials, with grave goodsMore elaborate burials, with grave goods Appearance and elaborate use of symbols Appearance and elaborate use of symbols
and works of art.and works of art.
Upper Paleolithic: The BladesUpper Paleolithic: The Blades
Blades begin roughly 40,000 Years BPBlades begin roughly 40,000 Years BP Comparative efficiencyComparative efficiency Levallois cores may produce 5 flakesLevallois cores may produce 5 flakes Many more blades could be produced from Many more blades could be produced from
same core--and with longer cutting edgesame core--and with longer cutting edge Unlike other traditions, blade traditions are Unlike other traditions, blade traditions are
shorter livedshorter lived Oldowan: from ca.2.5 m. yrs BP Oldowan: from ca.2.5 m. yrs BP Acheulean: from ca 1.9 m. yrs BPAcheulean: from ca 1.9 m. yrs BP
Upper Paleolithic AssemblageUpper Paleolithic Assemblage
Upper Paleolithic Tools (left to right): biconical bone Upper Paleolithic Tools (left to right): biconical bone point, Perigordian flint blade, prismatic blade core, point, Perigordian flint blade, prismatic blade core, Soluterean Willow leaf point, double-row barbed Soluterean Willow leaf point, double-row barbed harpoon point (various sites in France)harpoon point (various sites in France)
Homo florensiensisHomo florensiensis
Small skull found in Liang Bua Cave, Flores Small skull found in Liang Bua Cave, Flores Island, Indonesia, in 2004Island, Indonesia, in 2004
Other specimens found since thenOther specimens found since then Age range: 18,000 to 74,000 BPAge range: 18,000 to 74,000 BP Main attributes: rounded skull, chinless Main attributes: rounded skull, chinless
mandible, hominin postcranial skeletal partsmandible, hominin postcranial skeletal parts Fauna: Komodo dragons (large lizards), small Fauna: Komodo dragons (large lizards), small
elephantlike stegodons, and giant ratselephantlike stegodons, and giant rats Artifacts: Several small stone implements of Artifacts: Several small stone implements of
sizes appropriate to sizes appropriate to H. florensisH. florensis. .
Homo Floresiensis: The Homo Floresiensis: The ControversyControversy
Microcephalic human or separate Microcephalic human or separate species?species?
Same species: absence of thyroid Same species: absence of thyroid gland essential to growth, other gland essential to growth, other features similar to sapient form.features similar to sapient form.
Different species: no chin, skull Different species: no chin, skull structure similar to H. erectusstructure similar to H. erectus
Further debate: see pp. 314-315, Further debate: see pp. 314-315, Park textPark text
Overall consensus: likely a separate Overall consensus: likely a separate species but not all share in that species but not all share in that conclusionconclusion
To Sum Up: Representatives of To Sum Up: Representatives of Five SpeciesFive Species
The species:The species: 1. Australopithecus 1. Australopithecus
afarensisafarensis 2. Australopithecus 2. Australopithecus
africanusafricanus 3. Homo habilis3. Homo habilis 4. Homo erectus4. Homo erectus 5. Homo 5. Homo
neanderthalensisneanderthalensis