ANT 101 Final
Geographic distribution of H erectus
Homo erectus left Africa ~1.8 mya • Dispersed to Asia and Eurasia (Central and Western) • Global climate and habitat changes caused widespread movement • Oldest fossils found in Dmanisi, Georgia
Post-Orbital Constriction
Narrowing behind the orbits
Francis Galton
The philosophy of "race improvement"; idea that controlled selective breeding can improve the human species ▪ Eugenics movement in the Europe and the US ▪ Sterilization and anti-immigrant movement ▪ Nazi pseudoscience and idea of racial purity
Middle Pleistocene Hominins
Widely distributed: Africa,Asia, and Europe • For the first time, Europe becomes more densely occupied (e.g., France, Spain, Germany, Hungary, Italy) • Replacing, or coexisting, with earlier hominins (e.g., Homo erectus) in previously exploited habitats; range was not vastly extended Homo heidelbergensis
Modern Human Anatomical Features
Average cranial capacity: ~1350 cc • Small teeth • Small face • Canine fossa: Depression on the surface of maxillary bone caused by the socket of the canine tooth • Well-defined chin • Rounded skull with vertical forehead • Reduced supraorbital torus
Earliest Human Fossil Sites
Earliest fossils in Africa & Middle East (80,000- 190,000 ya), followed by Eurasia, Australia, and finally the Americas
(Cranial)Sagittal crest
Elevated bone along the midline of the cranium - Attachment site for muscles a bony ridge on the top of the skull to which the jaw muscles are attached.
Orthognathic
Flat face Having a non-projecting lower facial skeleton
Prognathism
Anterior projection of the midface Projection of the jaw(s) beyond the projection of the forehead.
Evidence for Ritual
Evidence for intentional and ceremonial burial ▪ Grave goods ▪ Forms of postmortem modification (e.g., dismemberment, defleshing)
Describing Human Variation
Historically, the dominant paradigm has been race and racial classification ▪ Used in many different ways: ▪ Continental ancestry ▪ Nationality ▪ Religious identity ▪ Ethnic or cultural group ▪ Race is often used in a social sense and can have biological consequences
Multiregional Evolution/Continuity
Homo erectus left Africa and then evolved into modern humans in several different locations throughout the world • All populations experienced similar patterns of change (i.e., continuity) due to gene flow and common modes of adaptation • Differences in genes and morphology due to adaptations to local environments • Modern humans are the most recent morphological form of Homo sapiens, which have been around for ~2 million years
Supraorbital torus
Robust piece of bone above orbits - Variability in prominence of brow ridge
Gracile
Slender bodied (versus robust)
The Great Rift Valley
• Formed ~8 mya • Stretches ~3,500 miles • Over 2,000 feet deep
Johann Blumenbach (1752-1840)
the socalled "father of physical anthropology" ▪ Defined the "classic" races in 1795 ▪ Caucasian ▪ Mongolian ▪ Ethiopian ▪ American ▪ Malay ▪ Field moves towards focus on the skull, era of measurement, and explicit hierarchy/ranking
Homo erectus
~ 1.8 million years ago - 143,000 years ago Africa, Asia, and Central/Western Eurasia ~727 - 1251 cc Cranial and Dental: Larger brain size; facial and dental reduction; low forehead; long and low braincase; pronounced supraorbital torus; pronounced occipital/nuchal torus; sagittal keel/ridge; thick cranial bones; cranium broadest at base; shovel-shaped incisors Postcranial: Larger body size (5.3 - 5.9 ft.); change in proportions (longer legs, shorter arms); similar stature to modern humans in equatorial Africa - First hominin to disperse from Africa; associated with Acheulean tool industry; first definitive evidence of controlled fire; the fossil "Turkana Boy" is the most complete Homo erectus skeleton
Homo neandertalensis
~130,000 - 30,000 years ago Europe and Western Asia ~1200 - 1740 cc Cranial and Dental: Large brain size; long skull ("football" shaped); prominent, arching brow ridges; midfacial prognathism; wide nasal aperture; retromolar gap; occipital bun; no chin Postcranial Large, robust, and muscular bodies; short limbs; barrel-shaped rib cage - Associated with Mousterian tool industry; buried dead; skilled large game hunters; evidence of using symbols and ornaments
Paranthropus robustus
~2.0 - 1.5 million years ago South Africa ~530 cc Cranial and Dental: Small brain size; pronounced sagittal crest; flared zygomatic arches; flat face; small incisors and canines Postcranial: Long arms but bipedal feet; similar hands to later hominins -Adaptations associated with a robust diet (i.e., low quality, hard-toprocess, fibrous foods); lived in mixed-sex groups of multiple adults and offspring
Laetoli (Tanzania) Footprints
-3.7-3.5 mya -preserved through volcanic ash footprints of two bipedal hominids preserved after a volcanic eruption and rainfall; 3.6mya
Multiple Dispersals and Assimilation
Most supported and accepted view now - Multiple dispersals of genus Homo out of Africa • "Out of Africa,Again and Again" - Modern humans originated in Africa, ventured out, and interbred with populations of archaic Homo sapiens • Evidence: - Recent fossil and DNA evidence support this view
Neandertal key sites
NeanderValley (Germany) -La Chapelle (France) -Shanidar (Iraq) -Mt. Carmel sites (Israel)
Australopithecus
Thrived in Africa for over 2 million years ▪ Habitual bipeds ▪ Small-bodied (3.5 - 5 feet tall) ▪ Slightly larger brains (yet still small) ▪ Large molars with thick enamel (fibrous diet) ▪ Small canines and reduced honing complex ▪ Limited tools and culture ▪ Lived in various habitats in east, central and south Africa (e.g., open woodlands, grasslands)
Homo heidelbergensis
Transitional species between H. erectus and later hominins (e.g., modern humans and Neandertals) - Pronounced supraorbital torus, thick cranial bones, and no chin, yet larger brains and reduced dentition ~600,000 - 200,000 years ago Africa, Europe, and Asia (China) Cranial Capacity:~1100 - 1450 cc Cranial and Dental:Less prominent and separated supraorbital tori; less pronounced sagittal keel; flatter face; decreased robusticity of cranial bones; larger brain size Postcranial: Tall (i.e., lower legs were relatively long); robust postcranial traits (e.g., leg bones were thick and strongly built) -Likely ancestor to bother Neandertals and anatomically modern humans; transitional species between Homo erectus and later hominins (e.g., modern humans and Neandertals)
Neandertal Fate
Between 30 - 40,000 years ago, Neandertals were joined in Europe by anatomically modern Homo sapiens • Genetic evidence indicates occasional interbreeding • Various hypotheses regarding the fate of Neandertals • Examples: Parasites and pathogens, competitive replacement, failure or inability to adapt to climate change
Foramen magnum
Big hole"; located on the inferior region of the skull A large opening at the base of the skull through which the brain connects to the spinal cord.
Tools
Blade industry ▪ Made from stone flakes ▪ Flakes are twice as long as they are wide ▪ Wood, ivory, and bone carved to produce small tools (e.g., fishhooks, needles) ▪ Atlatl (i.e., spear-thrower) ▪ Able to better exploit surrounding environment (e.g., collect fish, increased food processing) ▪ Regional variation and "style"
Zygomatic arch
Cheek bone
Oldowan Tools
Commonly regarded as first stone tools in the archaeological record • ~2.5 mya • Involve simple modifications • Potentially associated with increased meat eating • Core: Possibly used for heavy-duty chopping, butchering, and fracturing (e.g., bones) • However, some suggest that the core was not the main tool • Flake: Likely used for cutting, slicing, and sawing (e.g., wood, meat, grass) • Associated with earlier hominin species?
H heidelbergensis Cranial Features
Compared to H. erectus • Supraorbital tori: Less prominent and separated (arching), yet still large • Sagittal keel and occipital torus: Less pronounced • Robusticity: Decreased, yet some thickness of cranial bones • Brain size: Larger and vertical sides • Some within modern human ranges
Modern Human PostCranial Features
Compared to Neandertals ▪ Taller with a more slender body ▪ Thinner, less robust bones ▪ Longer limbs ▪ Longer trunk ▪ Cylindrical-shaped rib cage
Homo floresiensis
Discovered in 2004 • Age: ~100 - 12 kya • Location: Flores, Indonesia • Traits: • Tiny body (~3 ft.) and brain (~400 cc) • Skeletal similarities link H. floresiensis to H. erectus • Large supraorbital torus and thick cranial bones • Homo dentition • Human-like bipedal adaptations and modern proportions • Result of isolated dwarfism?
Australopithecus Diversification and Dispersal
Dispersal into South Africa ~3 mya • Diversification into gracile and robust forms • Gracile (South Africa only) -Australopithecus africanus • Robust (South Africa and East Africa) -Paranthropus robustus, boisei, aethiopicus
Argument
Early Homo fossils typically classified into two species (although debated) • Homo habilis • Homo rudolfensis
Nuchal
Posterior side of the neck Back of neck
Australopithecus anamensis
First Australopithecine ▪ Location: Northern Kenya ▪ Age: ~4.5 - 3.9 mya ▪ Ape-like features ▪ Slight canine/premolar honing complex ▪ Hominin-like features ▪ Bipedal modifications in lower limbs ▪ Molars with thick enamel ▪ Potential ancestors for later Australopithecines (e.g., A. afarensis)
Acheulean Tool Industry
First appear in Africa ~1.6 - 1.4 mya • Found mostly in Africa and western and central Eurasia; few locations in east Asia • Bifacial Flaking: Flaked on both sides • Strong and sharp hand axes • Preconceived shape; required a "mental template" • Carried from place to place • Used to process meat; also, possibly wood and bones
Pleistocene
Rapid climatic fluctuations occurred during the Middle Pleistocene (900 -130 kya) and Late Pleistocene (130 - 10 kya) • Glaciations: Associated with colder temperatures and continental ice sheets covering northern continents • Interglacials: Associated with warmer temperatures and reduction in continental ice sheets • Major effects in Europe and northern Asia; influenced gene flow and drift
Understanding Human Variation
Recent origin (within last 200,000 years) ▪ Widespread geographic distribution ▪ Patterns of gene flow and isolation ▪ Exposure to diverse environmental factors Humans are very similar in genotype - Genetic make-up of an organism • However, humans are significantly different in phenotype - Physical manifestation of the genotype (i.e., observable characteristics) • Difference between describing and understanding human variation
Neandertal Culture
Hunters • Able to hunt large game (e.g., bison, deer) in coordinated groups using long spears • Evidence of healed injuries similar to rodeo athletes • Tooth wear from processing hides • Provided assistance to injured individuals? • Buried Dead • Deliberately positioned in graves • Some evidence of "grave goods" • Symbols and Ornaments • Necklaces (e.g., shells) • Body pigments
determinant of genus Homo
Large brain relative to body size - 40% increase in brain size among early Homo compared to Australopithecines - Also, smaller teeth and larger body size
Neandertal Cranial Features
Large brain size (mean: ~1520 cc) ▪ Long skull ("football" shaped) ▪ Prominent, arching brow ridges ▪ Mid-facial prognathism ▪ Wide nasal aperture ▪ Retromolar gap: Behind 3rd molar ▪ Occipital bun ▪ No chin
Honing/Shearing Complex
Lower first premolar is sharpened from rubbing against the upper canine - Leads to honing of surfaces on both teeth Sectorial premolar: First lower premolar that exhibits compression due its role as a shearing surface - Diastema: Space separating teeth of different functions - Reduced among early hominin groups
Upper Paleolithic Cultural Period
Material Culture among Modern Humans ▪ Started ~40 kya ▪ Advent of modern humanity ▪ New complexity in tools, hunting and foraging behavior, and symbolic expression 12,000 year old bone needle
Hominin
Member of the subfamily Homininae ▪ Includes humans and ancestors in our lineage since LCA with apes ▪ Has replaced the term "Hominid" Defined by habitual bipedal adaptation Earliest Hominins ▪ ~5-7 million years ago (End of Miocene) ▪ Evolved in Africa and were there exclusively until ~2 mya Hominin evolution extremely complicated and species-rich • Often, multiple species alive at one time • Multiple hominin adaptive radiations • Not one linear progression from simple to complex
Turkana Boy
Most complete H. erectus skeleton ▪ Skull, pelvis, limb bones, ribs, and vertebrae ▪ Age: ~1.65 mya ▪ Location: W. Turkana, Kenya, E. Africa ▪ Brain size: ~900 cc ▪ ~8 years old, ~5'3" tall, and ~100 lbs. ▪ Similar stature to modern humans in equatorial Africa ▪ Long legs
Dental Arcade
Shape made by the rows of teeth in the upper jaw
Archaic vs Anatomically Modern Humans
Specific changes in the cranium distinguish "archaic" and "modern" humans Modern: • Small brow ridge • Flat face • Flat, small cheekbones • Small teeth Archaic: • Large brow ridge • Projecting face • Large, wide cheekbones • Larger teeth
Homo habilis
~2.0 - 1.6 million years ago East and South Africa ~503 - 661 cc Cranial and Dental: Encephalization (i.e., expanded brain size relative to body size); large incisors, smaller molars; precision grip (i.e., able to grip objects forcefully with hands); relatively prognathic face; no sagittal crest Postcranial: Pelvic and lower limb morphology display bipedal adaptations -Associated with Oldowan tool industry (commonly regarded as first stone tools in the archaeological record); name means "handy man"
Paranthropus boisei
~2.3 - 1.3 million years ago East Africa (Ethiopia, Tanzania, and Kenya) ~410 - 530 cc Cranial and Dental: Small brain size; pronounced sagittal crest; flared zygomatic arches; broad, dish-shaped face; very large molar teeth; parabolic dental arcade Postcranial: Few postcranial bones associated with this species -Adaptations associated with a robust diet (i.e., low quality, hard-toprocess, fibrous foods); lived in mixed-sex groups of multiple adults and offspring
Paranthropus aethiopicus
~2.5 - 2.3 million years ago East Africa (Ethiopia and Kenya) ~410 cc Cranial and Dental: Small brain size; dish-shaped face; pronounced sagittal crest; flared zygomatic arches; extreme facial prognathism; very large molar teeth Postcranial: Limited postcranial evidence of this species -Adaptations associated with a robust diet (i.e., low quality, hard-toprocess, fibrous foods); lived in mixed-sex groups of multiple adults and offspring
Homo ergaster
African • ~1.8 mya - 800 kya • East & South Africa • Separate species: Homo ergaster? • Large brain (~750-900 cc) • Lack of sagittal keel • Less robust supraorbital torus • Thinner cranial bones
Australopithecus bahrelghazali
Age: ~3.3 mya • Location: N. central Africa in Chad - Evidence for broader distribution of Australopithecines • Mandible fragment only • Highly debated hominin fossil - Some experts suggest that the mandible belongs to A. afarensis - Others suggest that it represents a separate species - "Lumpers" vs. "Splitters"
Recent African Origin ("Out of Africa")
Anatomically modern humans evolved in Africa (~150 - 200,000 years ago) and then ventured out of Africa and globally dispersed • RAO-Replace: Modern humans replaced archaic humans with minimal interbreeding • RAO-Hybrid: Modern and archaic humans engaged in interbreeding
Asian H Erectus
Asian • ~1.8 mya - 143 kya • West, East & SE Asia (Java, China) • "Classic" H. erectus traits • Large brain (~750-1250 cc) • Strong sagittal keel • Strong supraorbital torus • Thick cranial bones
Art
Elaborate cave paintings (by ~40,000 years ago) ▪ Example: Lascaux Caves in France (date to ~17,000 years ago) ▪ Painted onto the walls using mineral pigments Venus and Caves of Lascaux showing game
Carolus Linnaeus (1758)
First systematic attempt at human classification ▪ Assigned varieties or "races" ▪ Homo sapiens afer (Africans) ▪ H.s. americanus (American Indians) ▪ H.s. asiaticus (Asians) ▪ H.s. europaeus (Europeans) ▪ H.s. ferus ("wild men") & H.s. montrous ▪ Most early (18th & 19th century) classifications used some type of ranking system ▪ "Great Chain of Being": A universal hierarchical ladder ▪ Implied or explicit rank order of superiority from European to Asian to American to African ▪ Reflected worldview of Europeans at the time
Early Hominin Evolution
From late Miocene to early Pliocene
(Anatomically modern) Homo sapiens
~200,000 years ago - Present Geographical Location Throughout the world Cranial Capacity (if available) ~1000 - 2000 cc Cranial and Dental: Rounded skull with widest point toward top (on sides of parietals); canine fossa; tall, vertical forehead; small teeth; small face; well-defined chin; reduced supraorbital torus Postcranial: Tall with a slender body; thin, less robust bones; long limbs; long trunk; cylindrical shaped rib cage -Associated with Upper Paleolithic tool industry; evidence of cave art, symbolism, portable art, personal ornamentation, and ritual
Australopithecus africanus
~3.0 - 2.4 million years ago South Africa (e.g., Sterkfontein and Taung sites) ~450 - 500 cc Cranial and Dental: Small brain size; small canines and incisors; less prognathic face Postcranial Characteristics: Bipedal adaptations (e.g., curved lumbar region of vertebrae); arboreal adaptations (e.g., long arms, slightly divergent big toe) -Lived in woodland environment; Famous "Taung child" fossil discovered by Raymond Dart in 1924
Australopithecus afarensis
~3.9 - 3.0 mya Eastern Africa (e.g., Hadar and Laetoli sites) ~350 - 500 cc Cranial and Dental: Small brain size; prognathic face; anteriorly placed foramen magnum; reduced canine size yet still large; large molars with thick enamel; parallel-shaped dental arcade Postcranial:Lower limb proportions intermediate between ape and human (e.g., long arms); curved, long phalanges; pelvic and lower limb (e.g., femur, feet) morphology indicate of habitual bipedalism -Best-known early hominin; fossils from over 70 individuals have been discovered in east Africa; the fossil "Lucy" represents nearly 40% of a complete Australopithecus afarensis skeleton; Laetoli footprints found in association with Australopithecus afarensis fossils
Ardipithecus ramidus
~4.4 million years ago Middle Awash region of eastern Africa (Northern Ethiopia) ~300 - 350 cc Cranial and Dental: Non-honing canine; reduced prognathism; forward (anterior) foramen magnum Postcranial: Arboreal hands and feet (e.g., grasping big toe); mosaic foot (i.e., includes both arboreal and terrestrial features); long arms; bipedal pelvis and femur -Lived in a woodland environment; morphological characteristics suggest moved bipedally on the ground but was also adept at moving in the trees
Sahelanthropos tchadensis
~6 - 7 million years ago Central Africa (Northern Chad) Cranial capacity: < 400 cc Cranial and Dental Characteristics: Intermediate foramen magnum; small brain size; large brow ridges and cranial crests; small face No postcranial fossils have been found -Odd mixture of ape- and hominin-like features; expands the range of early hominins outside of eastern Africa
Orrorin tugenensis
~6 million years ago Eastern Africa (Central Kenya) Cranial capacity is unknown since no fossil material from the skull has been recovered Cranial and Dental:Thick molar enamel; partial honing canine Postcranial: Curved hand bones; long femoral neck and femur angled medially (valgus angle) -Postcranial material indicate bipedal locomotion; fossil name means "original man"
Australopithecus afarensis
• Best-known early hominin - Fossils of over 70 individuals from 6 different sites in E. Africa - "Lucy": Represents nearly 40% of a complete skeleton; ~3.2 mya • Age: ~3.9 - 3.0 mya Cranial features: 350 - 500 cm3, Prognathic face, Anteriorly placed foramen magnum Dental features: Canines reduced but still large, Large molars with thick enamel, "U-shaped"/parallel dental arcade Postcranial: Habitual Bipedalism - Pelvic morphology - Lower limb proportions intermediate between ape and human • Arboreal Adaptations: Curved, long phalanges, Long arms • Pronounced Sexual Dimorphism: Debated among paleoanthropologists • Weight: ~45 kg vs. ~29 kg • Height: 150 cm vs. 110 cm • Yet canines similar in size for both sexes
Distinguishing Cranial Traits H Erectus
• H. erectus has several unique features that distinguish it from early Homo and modern humans - Less facial prognathism and larger brain than H. habilis - Low forehead - Long and low braincase - Supraorbital torus - Occipital/nuchal torus • Pronounced ridge on rear-most occipital bone; neck muscles - Sagittal keel/ridge • Raised area where parietals meet on top of cranium - Thick cranial vault/bones - Cranium broadest at base - Dental reduction - Shovel-shaped incisors - No chin
Homo rudolfensis
• Questionable classification - Little postcranial material - Homo habilis, Paranthropus? • Age: ~2.4 - 1.6 mya • Location: East Africa • Encephalization: Brain size of ~700 cc • Body Size: Within range of modern humans (~5 feet tall) • Teeth: Smaller premolar and molars • Pelvic Girdle: Modifications similar to later Homo