Week 9-12 Flashcards
South African Australopithecines
- Australopithecus africanus
- first hominin ever found 2-3 Ma
Taung Child
- 3-4 years
- foramen magnum forward, showed upright posture
- small brain (450 cc) caused controversy
- thought human ancestors had larger brains
Reasons A. africanus is a Human Ancestor
- canine morphology (small, shaped like a human’s, wear pattern at the tip)
- anteriorly located foramen magnum (primarily bipedal)
- brain organization appeared more human-like (also based on endocast)
- ecology of Taung site (was not a tropical forest – not a typical ape environment)
Similarities Between A. africanus and A. afarensis
- bipedal and climbing features
- intermediate canines
- large incisors and molars
- cranial capacity ~ 450 cc
- sexually dimorphic (and short)
Differences between A. africanus
and A. afarensis
- A. africanus has:
- reduced canines
- deeper, more parabolic mandible
- face less prognathic
- dished face
Australopithecus phylogeny
- similarities between A. afarensis and A. africanus suggest simple interpretation
- A. africanus is continuation of A. afarensis
- more widely distributed in S. Africa
- shows some evolutionary changes
Australopithecus garhi
- Ethiopia 2.5 mya
- found incomplete cranium and part of limb
- cranium has large teeth and projecting face
- High degree of subnasal prognathism (nose sticks out)
What Environment did the Australopithecus garhi live in?
Paleoenvironment: open grassland near lake
Australopithecus garhi Different Features than Other Hominins
- long hindlimbs and long forelimbs
- limb proportions like Homo
- humerus/femur ratio like Homo
- found close to animal bones showing butchering
- signs of hunting animals
Australopithecus sediba
- 2.0 – 1.8 mya
- South Africa
- cranial capacity of juvenile = 420 cm3
- expanded cranium
- pelvis may be more like Homo
- transitional species between australopithecines and Homo habilis
- may be direct ancestor of Homo sapiens
What Environment did the Australopithecus sediba live in?
Paleoenvironment: open grassland
What are the 2 Species of the Hominin Divergence?
Gracile and robust australopithecines
Who Are The 4 Graciles?
A. afarensis, A. africanus, A. garhi, A.
sediba
Who Are the 3 Robusts?
Paranthropus aethiopicus, P. bosei, P.
robustus
Difference Between Gracile and Robust
Robust have larger body sizes and larger features than gracile (ex. crania and dentition)
Robust Australopithecines Traits
- 2.8 Ma
- East Africa: P. aethiopicus, P. boisei
- South Africa: P. robustus
- large (robust) molars
- small canines and incisors
- huge jaws
- sagittal crest
- flaring zygomatics
- small brain size
Paranthropus aethiopicus Traits
- single black skull found (mineralization)
- smallest adult hominin brain found (410cc)
- largest sagittal crest, most prognathic face, and largest molars of any hominid
- back teeth that are large compared to front
- large cheekbones (zygomatics)
- huge mandibles
What Environment did the Paranthropus aethiopicus live in?
Paleoenvironment: open grassland
Robust Features 1
- associated with chewing
- needed strong chewing muscles and huge back teeth
- dental wear analysis shows diet with lots of very hard materials
What did The Robust Eat?
hard materials like seeds, nuts, tubers
Robust Features: What is the Large Sagittal Crest Associated With?
- muscles of mastication (chewing)
- provides extra attachment space for extra strong chewing muscles
What Do the Chewing Muscles Attach To?
sagittal crest and zygomatics (cheek bones)
Paranthropus boisei
- from Olduvai, East Africa
- 2.3-1.4 mya
- discovered by Mary Leakey in 1959
- called “Zinjanthropus” and “Nutcracker man” due to very large mandible, large back teeth, and sagittal crest
P. boisei Traits
- large mandible
- large molars and premolars
- small incisors
- sagittal crest
- bigger brain (500 cc)
Paranthropus robustus
- found in Swarktrans and Kromdrai, South Africa
- lived 2-1.5 mya
- like East African australopithecines
- similar features as P. boisei, but not as large
- 490 cc cranial capacity
P. robustus Traits
- like East African robust australopithecines
- small cranial capacities
- large broad faces
- large molars and premolars
P. boisei is more robust than…
P. aethiopicus and P. robustus
Why P. boisei is more Robust Than P. aethiopicus and P. robustus?
P. boisei has smaller incisors and canines, heavier mandible, and an even shorter and broader face
What Are The Robust Features Associated With?
dietary behaviour
Australopithecine Tools
- called lomekwian tool tradition
- tools recently found on west bank of Turkana Lake in Kenya
- 3.3 mya
- stone tools with human processing (ex. large cutting board, anvils, cores, flakes)
- unique production method and style
Who Used The Lomekwian Tools?
A. afarensis or Kenyanthropus platyops
Hominin Evolution
- adaptive radiation of hominins in Pliocene
- like ape radiation in Miocene
Which 2 Species Lived in S. Africa At The Same Time?
A. africanus and P. robustus
Which 2 Species Lived in E. Africa At The Same Time?
A. garhi and P. aethiopicus in E. Africa
How Were They Able To Live In The Same Habitat?
Gracile and robust austropithecines occupy different dietary niches to avoid competition
Did The Ardipithecus Come Before or After Later Hominins?
Before
Are The Robust Australopithecines Descendants of Homo?
No
What Happened To The Robust Australopithecines?
developed a very specialized diet (eating varieties of foods) and went extinct
Who Is The Homo Ancestor?
Gracile australopithecine
Is Evolution of Homo a Straight Line or Bush?
Bush
Which Species Did Homo Evolution Descend From?
- A. garhi, A. afarensis, A. africanus or A. sediba
- oldest Homo species from 2.5 mya
How Is The Homo habilis Different From Earlier Hominins
increased cranial capacity (500-800 cc; mean=630ml) vs. 450 for gracile and 500 for robust australopithecines
H. habilis Traits 1
- larger front teeth relative to back teeth
- narrower premolars
- small browridge
- smaller face than Australopithecus and similar bipedal characteristics
- reduced molars
- foramen magnum more anterior
- short and broad pelvis
- arch in foot
H. habilis Traits 2
- larger brain
- smaller canines
- less prognathism
- parabolic dental region
- made and used stone tools
H. habilis Post Cranial
- strange body proportions with longer arms
- longer arms than A. afarensis
- upper limbs longer and thinner
- femur smaller and less robust
H. habilis & Tools
- first definite association of a hominin with stone tools (australopithecines may have used durable tools, but no evidence found)
- from around 2.5 mya
Oldowan Tools
- “cores and flakes”
- used crude tools that look like rocks
- have a few chips knocked off rock to make a sharp edge
What Do The Oldowan Tools Show Besides Being Crude (Primitive)?
- they imply ability of maker to imagine the tool he wants from looking at the stone, and picture the process needed
- attests to cognitive ability of toolmaker
What were the cores and flakes used for?
- cores for pounding
- flakes for cutting
How were Oldowan tools used?
tools show microwear: they were used for cutting and skinning meat, hammering bone, preparing vegetables, grasses, and wood
Who and how long did the H. habilis exist with?
Robust australopithecines for about 1ma
H. rudolfensis is H. habilis
- two specimens may be same species showing lots of variation or two different species
- KNM-ER 1813 and KNM-ER 1470
- KNM-ER 1813: 510cc, smaller face and less projecting teeth than australopithecines
- medium-size brain and derived facial morphology
H. habilis Controversy
- KNM-ER 1470: larger cranium but more projecting face (named as H. rudolfensis by some)
- larger brain (775 cc) but primitive facial morphology
- may be two H. habilis fossils OR H. habilis and H. rudolfensis
If both are just H. habilis then…
- high degree of sexual dimorphism
- high degree of variation within species
If H. habilis and H. rudolfensis then…
- much less variation within species (less than gorilla)
- we will group all as H. habilis
Who was the first hominin outside of Africa and when?
Homo erectus spanning over 1.5my
Where did H. erectus spread geographically to?
Africa, Europe, Asia
During which period?
Pleistocene (1.8 Mya – 10 kya)
Who is the ancestor of Homo erectus?
- Kenyanthropus platyops → Homo rudolfensis → Homo erectus
- Australopithecus sp. → Homo habilis → Homo erectus
- Australopithecus sp. → Homo habilis AND Homo rudolfensis AND Homo erectus (Adaptive radiation)
Which scenario is accepted by scientists?
- Australopithecus sp. → Homo habilis → Homo erectus
Who may the African groups be ancestral to?
H. sapiens
Which side branch may be evolutionary?
East Asian groups
The Pleistocene (Ice age)
- 1.8 Mya - 10 kya
- much of northern hemisphere covered with enormous masses of ice
- 15 major and 50 minor glaciations in Europe
Describe the Pleistocene Period
- radical shifts in climate, flora and fauna in Eurasia
- less rain during glacial periods, more rain between them
- glaciers would block route out of Africa due to desert expansion
- significant period for hominins
Where was the first H. erectus discovered?
- in 1891 in Indonesia (Trinil, Java)
- 1.8 mya
- skull cap & femur found
- “Java Man”
- By Eugene Dubois
Other H. erectus sites
- other finds in Indonesia and China (1.8 ma)
- East Africa (1.8-1.6 ma)
- Europe (700 ka)
- H. erectus found in Asia 1.8 ma suggests first hominin dispersal out of Africa 1.5-2 ma
H. erectus Brain Size
- mean cranial capacity = 900cc
- H. erectus shows 25 - 40% increase in brain size from H. habilis (500-800cc)
- prominent supraorbital ridge
- receding narrow frontal bone
- keel at midline
Relative brain size compared
to body size is…
similar to H. sapiens
Compared brain structure…
- different from h. sapiens
- not as encephalized (increase doesn’t match complexity compared to body size)
H. erectus Body Size
- dramatic increase in body size
- robust bodies with heavy builds (cold temps)
- longer legs, shorter arms (like modern humans)
- a committed terrestrial biped
- > 100 lbs, mean adult height of 5’6”
- sexual dimorphism (20%)
Thick postcranial bones unlike…
robust australopithecines that had robust crania
Cranial Shape 1
- distinctive shape due to increased body size/robusticity
- thick cranial bones
- lemon shape at back of skull
- thick cranial bones
- large brow ridges – supraorbital torus
- little forehead development
Cranial Shape 2
- long, low cranial vault
- cranium wider at base than earlier or later hominins
- cranium widest below ear opening
- sagittal ridge: small ridge along midline of skull
What is a distinguishing characteristic of H. erectus?
nuchal torus where neck muscles are attached
H. erectus Dentition
- teeth like modern H. sapiens
- intermediate in size between H. habilis and H. sapiens
- back teeth in size range of H. sapiens
- shovel - shaped incisors (scooped out appearance in Asian pop)
- may relate to food processing, but no proof
Drimolen (South Africa)
- earliest H. erectus from 2 mya
- fragments of upper part of skull
- 2-3 years old
- 2.04 – 1.95 mya
- small cranial capacity of ~550 cc
Koobi Fora (Kenya)
- complete skull with no mandible
- 1.8 mya
- cranial capacity ~850cc (small)
- not surprising given that one of oldest H. erectus fossils
- probably female
- thick brow ridges
Nariokotome (Turkana) Boy
- second most complete fossil
- 12 year old boy (approx. 9-12)
- young adolescent stage of development
- 5’6” (would have been 6’ as adult)
- cranial capacity at adulthood ~909 cc
The Nariokotome Boy and Lucy
- H. erectus has longer legs than A. afarensis
- H. erectus postcrania are more like H. sapiens than A. afarensis
- body size and proportions, chest shape
Rapid spread of H. erectus
- after speciation 2mya
- out of Africa 2-1.8 mya, through SW Asia
- migration: small groups split off in search of resources
- last stop Java (at the time was connected to mainland SE Asia by a landbridge)
Why did they leave Africa?
- increase in population numbers
- adaptive flexibility to exploit different habitats
- following big game
- curious
Homo erectus in Asia
- in Georgia, Indonesia, China
- must have colonized Asia relatively quickly after evolving in Africa
Where were the olddest H. erectus remains found outside of Africa?
Georgia 1.9-1.78 mya according to absolute dating
Dmanisi, Georgia
- look like E. African H. erectus
- mandible discovered in 1991 has most postcranial remains plus complete dentition, but no crania
H. erectus from Dmanisi compared to African H. erectus
- small faces and jaws
- variable browridges depending on skull
- less developed browridges (still big) overall, but one skull has huge browridges
- cranial capacity of 650cc (smallest for H. erectus)
What tools did they find in Dmanisi?
- similar to Oldowan core and flake industries in E. Africa
- simple re-touching of tools
- no new tool technologies
Homo erectus from Indonesia
- most fossils from 800 kya
- one is 1.8 ma, one is 1.6 ma
- cranial capacity of skullcap 940cc
- prominent supraorbital ridge
- receding narrow frontal bone
- keel at midline
Sangiran, Indonesia
- cranial capacities = 813 – 1059cc
- oldest fossils are >1ma, others are 0.6-1 ma
Ngandong, Indonesia
- cranial capacity - 1150 cc
- supraorbital torus has double arch shape
- occipital and nuchal plane same size
- called “Solo Man” because found near Solo River
- dating controversial - 50-25 Kya?
- very late survival of H. erectus in Java?
- may have lived at same time as H. sapiens
- no artifacts found, so little known about way of life
Zhoukodian, China
- Mammalian bones (“dragon bones”) had been used historically in Chinese medicine
- fossils shipped to NYC when Japan invaded China in 1933, but went missing and never found
- largest number of specimens from one site
- from less than 700kya (700-250ka)
- “Peking Man” from 578 kya
- skullcaps and stone tools found in same layer
- 40-45 individuals
What was the life span of the H. erectus living in Zhoukodian, China?
- 40% of bones from individuals less than 14 yo
- 2% from individuals over 50
Zhoukodian H. erectus
- typical H. erectus features
- supraorbital torus
- nuchal torus
- sagittal ridge
- protruding face
- shovel-shaped incisors
Zhoukodian Artifacts 1
- indicate site was occupied for 250ka intermittently
- earliest tools are crude, but more refined over time
- mostly choppers (Oldowan)
- retouched flakes made into scrapers and points
- used stone, bone, and horn
- antler used as hammers and sharp edges as digging sticks
- deer skulls with evidence of whittling and only braincase intact – used as drinking bowls
Zhoukodian Artifacts 2
- remains of deer, horse bones, ostrich eggs, and seeds
- likely hunter-gatherers
- some bone tools appear to be needles
- likely wore clothes
- lived in cold environment
H. erectus evidence for use of fire
- first species to create fire
- layers of ash in Zhoukodian cave
- Also found at other sites in Africa and Europe
- more likely campfires rather than natural fires
- 599-240kya at Zhoukodian, 1.6 ma at Koobi Fora, Swartkans 1.5-1ma
- likely first species to make and use fire
- fire provides warmth and also meant cooking with heat
- major change to lifestyle
When did the H. erectus leave Africa?
1.8 ma
H. Erectus Traits Summary
- bigger brains and more advanced tool technologies than H. habilis
- used other durable materials for tools besides stone
- capable of controlling and making fire
- likely wore clothing
- likely were hunters and gatherers
Acheulian Tools
- used in Africa, Asia, and Europe by Homo erectus
- oldest from 1.4 ma in Africa, persisted there, W. Europe, and SW Asia for 1ma
Where are the Acheulian tools not found in?
E. Europe or E. Asia
Movius Line
- theoretical line drawn across N. India, proposed by archaeologist Hallam Movius
- technological difference between tool technologies of H. erectus in east and west
What tools did the West Asian H. erectus use?
Acheulian tool technologies
What tools did the East Asian H. erectus use?
Oldowan tool technologies
Why did the East Asian H. erectus only use Oldowan tools?
lack of appropriate materials to make rocks which stopped the practice of tool making
Archaic Homo
- may be a transitional species between early Homo and modern Homo sapiens
- modern-sized brain with primitive looking cranial morphology reminiscent of Homo erectus
- A LOT of variation
- “wastebasket” classification category
- dont fit intp erectus, Neanderthal or sapiens
- Africa, Eurasia, Australasia
- 400 – 130 kya
Archaic Homo names
- H. heidelbergensis
- H. antecessor
- H. rhodesensis
- H. helmi
- H. rudolfensis
Archaic Homo erectus-like features
- large supraorbital torus (brow ridges)
- thick neurocranial bones
- no chin
- total facial prognathism
Homo sapiens-like features
- large brain (1220 cc avg)
- tendency toward rounder occipital bone in skull
- supraorbital torus arched over each eye
- decrease in cranial and post-cranial robusticity from H. erectus
Archaics: Dentition
- smaller molars
- retromolar gap (Neanderthals): space behind last tooth
Broken Hill (Kabwe), Zambia
- found from 150,000 - 125,000 ya
- erectus traits: supraorbital torus long low cranial vault
- modern traits: cranial capacity: 1280-1285 cc, thinner cranial bones
Archaic Homo: China
- Zhoukodian and Dali sites
- from 200,000 ya
- H. erectus features: small cranial capacity (1120 ml), sagittal ridge and flattened nasal bones
- H. sapiens features: thin cranial bones
Archaics in Europe
- Many between 400,000 - 150,000 ya
- transitional features; mixture of H. erectus and modern H. sapiens traits
Who are the Atapuerca specimens closely related to?
Neanderthals
Archaics in Europe resemble H. erectus
- thick cranial bones
- less round cranial vaults
- cranium widest below ears
- similar postcranial skeletons
- these middle Pleistocene European hominins are too primitive to be considered modern H. sapiens or Neanderthal
Differences between European Archaics and African and Asian Archaics
- Africa and Asia: trend towards modern H.sapiens traits
- Europe: trend towards Neanderthal traits
Archaic Homo Culture 1
- tools used by middle Pleistocene hominins are similar to those used by Homo erectus
- Acheulean hand axes still dominate the tool kit in most places
- Tools use started to change around 250 kya everywhere except E. Asia
- Hand axes become less common
Archaic Homo Culture
- replaced by tools made from large flakes that were then further shaped by the Levallois technique
- Levallois method controlled flake size and shape: scraper, point, spearhead
- more sophisticated tool technology
- In Asia, Oldowan tool kit still used
Levallois Technique
- required several steps, suggested increased cognitive abilities
- shift in tool culture not associated with any morphological change in hominins
- appeared at around same time in Africa and Europe even though hominins living in those regions were morphologically different
Where did the Archaics live?
- caves and open-air sites, but probably increased use of caves
- used and controlled fire
Lazaret Cave (France)
- shelter against cave wall
- base supported by rocks and bones
- skins hung over poles
- 2 hearths inside structure
- fished for trout and carp
- ate many foods
- used seaweed as bedding
- around 130kya
Terra Amata (France):
- short-term visits to shelters
- seasonal occupation
- evidence of post holes and multiple shelters
- 400kya
Archaic Hunting Abilities
- up for debate: may have been more or less advanced
- two sites show evidence of advanced hunting abilities
Hunting: La Cotte de Saint-Brelade (France)
large mammal skeletal remains in association with stone flakes
Hunting Schoningen (Germany):
- wooden spears next to mammal bones
- spears were constructed to be thrown
- from 400 kya
Hominin phylogeny and Neanderthals
- early Homo led to Homo erectus and archaic Homo
- Neanderthals and modern H. sapiens branched off from one another
- Neanderthals are evolutionary dead end
- lived 130-35 kya
Neanderthals
- appeared in Europe 130kya and had drastic expansion
- lived in W. Europe, Israel, Near East
- first discovered in 1856 in Neander Valley, Germany – very robust first specimen found
- lived approx. 130-35 kya, but some specimens as old as 300ky found
Neanderthal stereotype
- robust first fossil find led to stereotypes of Neanderthals as “big, stupid brutes”
- current popular reconstructions suggest they were much more like modern humans
Neanderthal Morphology
- large cranial capacity: 1250-1700ml, average 1500
- even larger than modern H. sapiens
- also has increased body size compared to modern humans
- increased size may be due to increased metabolic efficiency in cold climate
- ex. modern Inuit have larger bodies and brain sizes, and are cold-adapted
How are Neanderthals cold adapted?
- very large nasal aperture
- more surface area to warm air
- large infraorbital foramina (large holes located beneath the eye orbits)
- allowed for more blood flow to face to prevent frostbite
- stocky trunk and short limbs retain heat
- bodies follow (Bergmann’s and Allen’s Rule
Bergmann’s Rule
- smaller bodies are adapted to hot environments (ex. birds)
- larger bodies are adapted to cold environments (ex. Neanderthals)
Allen’s Rule
- an animal’s limb lengths are heat-related limbs are
- longer in hot environments and
shorter in cold environments (ex. Neanderthals)
Neanderthal Cranial Morphology
- cranium was large, long, low and bulging at sides
- thin cranial bones
- occipital bun (bun-shaped occipital bone in rear of cranium)
- low forehead that rises more vertically than H. erectus
- arched brow ridges
- midfacial prognathism
- lack of chin
Neanderthals Traits
- ~1520 cc
- bigger temporal bulge
- more prognathism
- retromolar gap (space behind molars)
- worn incisors – teeth may have functioned as tools
- decreased molar size
Modern Humans
- ~1350 cc
- smaller bulge
- less prognathism
- no retromolar gap
- incisors not worn
- increased molar size compared to body size
Neanderthal Dentition
- retromolar gap
- heavily worn (and large) incisors
- decreased molar size
Neanderthal postcrania
- robust, muscular bodies
- short and stocky – 5’5’’ avg. male, 5’1’’ avg. female height
- rib cage larger and more barrel-shaped
- weight-bearing joints are larger
- shorter and thicker limbs
- weighed around 30% more than humans of comparable height
- similar body type to humans that do heavy throwing (ex. shot put)
La Chapelle-aux-Saints (France)
- nearly complete skeleton in flexed position
- bones and tools placed around body (burial)
- 55 ky
- older male – indicates longer lifespan and care for elders
- ~1620 cc
- arched brows
- occipital bun
Teshik-Tash (Uzbekistan)
- Easternmost Neanderthal discovery
- 9 year old boy
- deliberately buried
- surrounded by 5 pairs of wild goat horns, indicating burial ritual
Shanidar (Iraq)
- 9 individuals
- deliberate burials (buried with flowers)
40 year old male…
- he had injuries: fractured eye socket (probably blind) and foot
- to survive, he was likely helped by others in group which shows evidence of care for elderly and disabled
Who were the first hominin to bury thier dead?
Neanderthals
Neanderthal Burials
- evidence of burials from 90-100 kya
- evidence from across Neanderthal sites
- placed in grave in curled up, flexed position
- used grave goods in burials: stone tools, animal bones, flowers, stone slabs on top of burials
- indicates symbolic behaviour
Neanderthal Hunting
- remains of animal bones show they were successful hunters
- many stone tools found with animal bones, especially parts of animal with most meat
- were selective about animal species hunted and killed prime-aged animals (not old or sick animals)
What did Neanderthals eat?
- ate meat, berries, nuts, other plants
- isotope study shows heavy reliance on meat for diet
Neanderthal hunting and injuries
- had only short-range hunting weapons, so had to get close to prey and risk serious injury
- used spears rather than projectiles
- high proportion of head and neck injuries
- close encounters with large animals, like modern rodeo performers
Neanderthal Abilities
- wore clothes (for warmth in the harsh climate)
- developed methods of curing skins
- no evidence of needles, so clothes were probably very simple
- fire regularly used (for cooking, warmth, light, keeping predators away)
