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You are what you eat!

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You are what you eat! The headhunter is not content merely to possess the skull, but opens it and takes out the brain, which he eats in order by this means to ... – PowerPoint PPT presentation

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Title: You are what you eat!


1
You are what you eat!
The headhunter is not content merely to possess
the skull, but opens it and takes out the brain,
which he eats in order by this means to acquire
the wisdom and skill of his foe GHR von
Koenigswald Diet underlies many of the
behavioural and ecological differences that
separate species, and so is important in defining
niche, with all its implications for the ecology
and evolution of extinct forms Peter Ungar, 2003
Dr. Susannah Thorpe, Rm W126 Email
S.K.Thorpe_at_bham.ac.uk
2
Homo erectus
  • Glacial conditions
  • Cave / sapling shelters
  • Fire
  • warmth
  • protection
  • cooking?

3
Chimpanzee diet
  • Fruit, insects, leaves, bark, meat (monkeys,
    pigs, small antelope)
  • Hunting mostly males, cooperative specific
    roles
  • Gombe ca.150 red colobus monkeys killed during
    peak hunting year
  • Peak male chimp meat consumption near lower end
    of human consumption (5-10 of diet)
  • Excited by meat, crave it, chew it long and
    thoughtfully, usually with a mouthful of leaves
    added
  • Social event shared between hunters/ kin/ allies
  • Infanticide- Banana provisioning?

4
Chimpanzees medicinal plants
  • Medicinal plants pith or leaves of plants with
    medicinal properties
  • know when they need it
  • knowledge to select particular species that are
    not part of normal diet
  • Tongwa people eat the same plants for medicinal
    use
  • unpalatable, chimps swallow them like pills
    rather than chewing the leaves
  • Contain an antibiotic against bacteria, viruses,
    fungi and parasitic worms

5
Australopithecines
  • Tooth shape evolves to improve mechanical
    efficiency for chewing . - tooth morphology
    differs among species adapted to different diets
  • Teeth dominate fossil hominin assemblages
  • Fossil hominin teeth generally very worn, - cant
    use standard measures for measuring cusp shape
  • Afarensis (top)
  • H. erectus (bottom)

6
Australopithecines Topographic analysis
  • Laser scanner - generate 3D points along the
    surface of a tooth
  • Geographic information system (GIS) - model and
    characterize the surface points
  • Score teeth by wear stage - compare shape data
    among similarly worn specimens of different
    species

(Unger 2004)
7
Australopithecines Topographic analysis
  • Occlusal relief
  • high (h)
  • low (l)
  • Cusp shape
  • sharp (s)
  • round (r)
  • blunt (b)
  • ? occlusal relief and steeper cusps ? efficiency
    in fracturing tougher, more deformable foods
    (leaves)
  • ? occlusal relief and ? steep cusps ? efficiency
    in fracturing brittle, less deformable foods
    (nuts/seeds/hard fruits)

8
Australopithecines Topographic analysis
A gorilla B chimp C early Homo D A. afarensis
  • Gorilla gorilla have the steepest slopes and most
    relief ? early Homo ? Pan troglodytes ? A.
    afarensis which has the flattest slopes with the
    least relief

(Ungar 2004)
9
Australopithecines Topographic analysis
  • Dental morphology reflects adaptations to primary
    foods, and also to less frequently eaten but
    still critical ones
  • Gorillas ? occlusal relief and steeper cusps ?
    efficiency in fracturing tougher, more deformable
    foods (leaves)
  • Both prefer soft fruits but gorillas can take
    advantage of fallback foods that are less
    accessible to chimps

A gorilla, B chimp
10
Australopithecines Topographic analysis
  • A. afarensis- ? crown relief and ? sloping
    occlusal surfaces than gorillas or chimps
  • more efficient fracture of brittle, less
    deformable foods but less efficient fracture of
    tough, more deformable foods
  • ? preferred soft, sugar-rich fruits, but would
    have been able to make better use of hard,
    brittle resources as fallback foods given
    seasonal availability
  • of favored items

Gorilla gorilla (A) Pan troglodytes (B) Early
Homo (c) A. afarensis (D)
11
Early Homo Topographic analysis
  • Early Homo intermediate bw chimps gorillas in
    slope and occlusal relief, ? intermediate in the
    fracture properties of the foods to which it was
    adapted
  • ? ? efficiency in fracturing tough, pliant foods
    than chimps or A. afarensis
  • thinner enamel sharp edges at sites of dentin
    exposure with wear would improve shredding and
    slicing efficiency
  • What tough foods were available to early Homo?
  • Meat tough and elastic. gt occlusal relief and
    steeper sloped cusps yield sharper cutting
    surfaces reduces meats ability to stretch and
    absorb energy, ? thwarts major toughening
    mechanism

12
Paranthropus boisei
  • Ungar A. africanus Paranthropus lived at
    different times at Sterkfontein
  • A. Africanus steeper molar cusps
  • Paranthropus large, crushing teeth (roots/seeds)
  • Did climatic swings lead to reduction in food
    sources for Paranthropus?

13
Did H. erectus hunt or scavenge?
  • more food per square mile of the African savannah
    than plant food
  • more effective energy source
  • venison 572 cals per 100g
  • fruit/veg lt100 cals per 100g
  • Reduced risk of seasonality, esp. in Northern
    temperate zones

14
Zhoukoudian (China), 400,000ya Peking man
Ash, choppers, flake tools fossilised remains
of H. erectus Cosy domestic scene, with H.
erectus using fire for warmth, protection and to
cook meat Did fire played a regular or
important role in the daily life of the
inhabitants?
15
Zhoukoudian (China), 400,000ya Peking man
  • Certainly some evidence of fire, but Lewis
    Binford
  • Many of the extensive ash layers may be results
    of the decalcification of massive organic
    deposits (including bird droppings, bat guana,
    hyena faeces)
  • Fires could have been a result of the accidental
    ignition of the organic material, which then
    smouldered for some time
  • Binford found no hearths, or any association
    between ash, stone tools and H. erectus fossils
  • So although had all the ingredients of a cosy
    domestic scene the ingredients were not related

16
Zhoukoudian (China), 400,000ya Peking man
  • Little evidence of cooking food. A few burnt
    bones (2 roasted horses heads), but other burnt
    bones had been meatless when put in the fire ?
    caught up in smouldering organic material
  • Binford et al
  • hyenas responsible for most of the materials in
    the cave
  • H. erectus scavenged from hyenas (hyena gnaw
    marks underneath hominid stone tool cut marks on
    some bones)

a
b
a hyena, b stone tools
17
But,
  • Stone tool evidence
  • Schick Toth wear patterns experimental
    studies -Acheulean hand axes cleavers were used
    for extensive meat eating
  • Anatomy (size and shape) Alan walker
  • H. erectus
  • comparable to top 17 of modern human pop. in
    height and mass
  • anatomical stasis (early forms very similar to
    late forms)
  • ca.1/3rd larger than H habilis and H rudolfensis
  • Could scavenging really have brought about a
    change of this magnitude?

18
Brain size vs. gastrointestinal tract
  • H. erectus 27-62 increase in brain size
    compared to early H
  • Earlier species had funnel shaped rib cages and
    pot bellies like living apes
  • H. erectus probably first hominid type to show
    a barrel-shaped thorax and a distinct waist
    similar to modern humans
  • significant decrease in size of gastrointestinal
    tract

19
Mass-specific organ metabolic rates in humans
Organ Metabolic weight in W. Kg-1 (watts per kg)
Brain 11.2
Heart 32.2
Kidney 23.3
Liver gastro-intestinal tract 12.2
Skeletal muscle 0.5
Lung 6.7
Skin 0.3
  • Brain mass specific metabolic rate c.9x average
    rate for body
  • Liver/gastrointestinal tract mass specific
    metabolic rate c.9.8x average rate for body
  • 2 ways to accommodate the increased energy
    demands of the large brain of HE
  • raise the overall basal metabolism rate of the
    body or
  • compensate for brain growth by reducing the size
    of another metabolically expensive organ

20
Organ weights
Observed human organ weights in comparison to
expected weights for a mammal our size
Humans same standard basal metabolism rate for
mammals our size but we have much bigger brains
and smaller gastrointestinal tracts than
expected The energetic savings from reducing the
digestive system c. added cost of larger
brain ? beginning w. HE, humans experienced an
evolutionary trade off of intestines for brains
21
Dietary implications
Food quality Food quantity/ processing time Intestinal requirements
poor quality (low energy) / hard-to-digest (e.g. gorillas) eat a lot process it slowly large stomach and intestines
high quality (high energy) / more digestible diets (e.g. carnivores) less food smaller organs for digesting it
  • By hunting H. erectus accessed energy rich food
    source
  • Only hunting would have provided enough
    consistent protein for this to take place
  • Surplus energy was used to feed hominin brains,
    which began to grow significantly

Meat eating
Brain enlargement
clever ways to obtain more meat
22
How did they hunt?
  • Methods to study early hominin behaviour

A Living system in the present
D Living system in the past
A Kalahari hunter gatherer Behaviour
(ethnographic observation)
D Prehistoric hunter gatherer behaviour
(archaeological observation)
B Contemporary fossil record
C Fossil record
B Material and organic debris of hunters and
gatherers
C Archaeological record (excavation)
Analogue from present to past
23
How did they hunt?
  • African hare quick but vulnerable
  • when the hare is about to dodge, it lays its ears
    all the way back
  • seeing this hunter veers L or R (50 chance of
    being right)
  • if hunter guessed wrong, the hare will usually
    run for cover and stay there without moving
  • primates highly developed colour vision will see
    through the camouflage

24
How did they hunt?...persistence hunting
  • Insight into animal behaviour e.g. antelopes and
    gazelles move in an arc when trying to escape
  • key persistence, keep it in constant motion
    until exhaustion
  • Tarahumara Indians of Mexico pursued a deer for
    2 days. Never loose track of its spoor
  • Supported by H. erectus anatomy
  • Barrel shaped rib cages ? high levels of
    sustained activity. Ventilation of the lungs
    enhanced by the ability to raise the upper part
    of the rib cage (enlarging the thorax) when
    taking deep breaths
  • Waist allows upper body to twist at the abdomen
    and arms to swing freely stabilises upper body
    in B. running
  • Human leg muscles capable of producing large
    forces

25
How did they hunt?... stalking, driving ambush
  • Chimps do it
  • Torralba and Ambrona (Spain, 400kya, Acheulean)?
    H. erectus hunters driving elephants, horses,
    deer rhinos into marshy bogs, killing them
    butchering them
  • Reanalysis (Klein Shipman 1980s) ?hominins (H.
    erectus/ heidelbergensis) used some of the
    carcasses (cut marks), no conclusive evidence of
    actual hunting
  • ? scavenging the remains of animals that had died
    naturally or killed by carnivores
  • 1st confirmed driving/ambush ? La Cotte de St.
    Brelade (Jersey) mammoth and rhino drives
    (240kya-125,kya). H. heidelbergensis

26
Cannibalism
  • Zoukoudian human skulls faceless had been
    opened at the base
  • ? cannibalism - eating the brains of the dead
  • a lack of humanity or culture (spiritual
    notion that cannibalism could increase their
    powers)
  • cannibalism in recent times the act is nearly
    always carried out as a ritual not for food
  • Distinction between dietary and ritual
    cannibalism extremely important its very rare
    for people to eat other people merely for food

27
Cannibalism
  • but,
  • Lewis Binford hominin remains are found in
    deposits containing many other bone fragments,
    including numerous predators (e.g. Chinese hyena)
  • The removal of the faces/ destruction of the
    skull base what happens when gnawing carnivores
    chew out the face of their prey
  • Fossils disappeared in WWII

28
Cannibalism
  • Middle awash in Ethiopia (Tim White)
  • curious marks on the skull of H. erectus
    forehead of the individual and around and inside
    the left eye socket
  • ? scalping removing tissue from the face
  • Why would another hominid have done such a thing?
  • Whether it remains cannibalism, head hunting, or
    some other behaviour remains a mystery at present
  • Indicates developed culture

29
Conclusion
  • Nomadic - following migrating herds problems
    transporting food and water
  • No direct evidence
  • ? bags made of animal hides containers made of
    wood, leaves, clay?
  • Material for toolmaking - probably transported,
    tools often made at the butchery site
  • Cooler climates may have stimulated the
    control/use of fire and the construction of
    clothing (animal pelts, e.g. Terra Amata bedding)
  • All these behaviours can be related to meat
    eating
  • Put an even higher premium on continued and
    better access to meat
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