90719
External
Achievement
Standard
Taxonomy
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Kingdom
Phylum
Class
Order
Family
Genus
Species
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Animalia
Vertebrata
Mammalia
Primates
Hominidae
Homo
Sapiens
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Kind
Professors
Can
Often
Fail
Good
Students
Why are we in these groups?
 Kingdom: Animalia
 Conscious, not plants or protists
 Phylum: Vertebrata
 Have vertebral column
 Class: Mammalia
 Milk feeding, live young
Order: Primates
 Adaptations associated with arboreal (tree) life
 1. Pentadactyl limb
 Five digits (most mammals have lost at some)
 Bones of lower arm and leg are separate giving more mobility (most
mammals have at least partly
fused now)
 Plantigrade foot posture where
the entire foot contacts the
ground
 Forelimbs prehensile (can
grasp objects – branches)
Order: Primates
 2. Eyes
 Eyes face forwards
 3. Stereoscopy (3-D Vision)
 Binocular vision in which the visual fields overlap
 Brain receives input from both eyes to both sides of the
brain giving ability to judge distance
Stereoscopy
Order: Primates
 4. Colour vision
 Photoreceptors- Rods and cones on retina
 Important for identifying edible fruit
 5. High Visual Acuity
 Can see fine detail due to the fovea (sensitive spot on the
retina with a nerve fibre per photoreceptor rather than
one per group)
 Precision
Order: Primates
 6. Well developed clavicle
 Helps with weight bearing, swinging and grasping
 7. Skin
 Tips of the fingers and toes have ridges which increase
the sensitivity to touch
 Precision
 8. Nails instead of claws
 Give broad base of support for fleshy end of
finger- good for grasping
Order: Primates
 9. Smell reduced- can not use this to track prey
 10. Highly developed balance and awareness of body in
space (Proprioception/ Kinaesthetic awareness)
 Essential for balance up trees, and ability to sense limb
positions in space
Order: Primates
 11. Very large brain
 Essential for processing information rapidly
 12. Reproduction
 Invest greater resources in each offspring
 Long gestation as young need to be developed
 Carry young
 Singular young
 Pectoral mammary glands as young suckle in sitting
position
Order: Primates
 13. Singular uterus
Order: Primates
 14. Sitting posture
 Sit in an upright manner to enable head movement
without affecting balance
Order: Primates
 15. Social life: Live in groups
 Protection
 Find food
 Learn
 Find mates
 Rearing of young
Family: Hominoids
 Apes rather than monkeys (Old World Monkeys
family: Cercopithecoidea)
 Apes, gibbons, orangutan, chimp, gorilla, humans
 Same as Cercopithecoidea as have
 2 premolar teeth in each half of each jaw
 Menstrual bleeding
 DIFFERENCES RELATED TO Brachiation
 Swinging in Branches by arms
Family: Hominoids
Brachiation
 1. Very powerful arms that are longer than legs
 2. Flatter chest
 3. Scapular is at the back rather than the side
 4. No tail
 5. Can supinate forearm
 6. Larger clavicle
Family: Hominoids
Brachiation
 7. Short lumbar region of spine
 8. More highly developed brain
 9. Lower molars have a Y-5 cusp patter
 10. No sitting pads (Ischial callosities)
 11. African Apes: Knuckle walking
 Describe how each of the following can be related to
arboreal life
 Ridges on the skin and fingertips
 A well developed clavicle
 Separate tibia and fibula
 Production of single young
 Long gestation period
 Stereoscopic vision
 Colour vision
 Large brain
Family to Genus…
 The family of Hominoids splits into
 Genus 1: Homo
 Genus 2: Australopithecus
Genus: Homo
 Large brain
 More ‘human’ like
Genus: Australopithecus
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Bipedal
Brain significantly smaller but bigger than a chimp
Canines reduced and non protruding
Shorter
Large degree of sexual dimorphism
No evidence of stone tools but perhaps stick tools
(Now extinct)
 Other genus:
 Chimps, Bonobos- Pan
 Gorilla- Gorilla
 Orangutan- Ponga
Species:
Homosapien
 Bipedalism
 Humans are the only
primates that can stand
and walk on two legs for
extended periods of time
Species: Homosapien
 Bipedalism
 1. Body
 is concentrated into a narrow column above feet
therefore body weight is supported by bone
 2. Skull
 Foramen magnum is situated in the middle of the
skull as opposed to being at the rear as in apes
Species: Homosapien
 3. Backbone (COG)
 Has a gentle S shape to take weight directly above hips
 Apes have one curve and weight is carried forward of
hips
Species: Homosapien
 4. Short hip girdle
 In quadrupedal species the hip bone is longer
 Humans have a bowl shaped hip bone which is smaller
 This help to transmit and carry weight better
Species: Homosapien
 5. Knee joints
 Directly below hip
girdle so can walk
without swaying
 When one leg is
lifted, the other is
only slightly out from
the center of gravity
so less tendency to
sway
 A chimp has to lean
the other way to keep
balanced
Species: Homosapien
 6. Foot
 Human foot is a platform through which thrust occurs
to push forward
 Large big toe that points forward
 Chimps foot is a prehensile structure therefore big toe
points sideways
 High arch in human foot to make long distance walking
possible
Species: Homosapien
 7. Hand- Thumb
 Longer
 Saddle joint that allows opposition
 Flexor pollicis longus flexes the tip of the thumb
 Gives precision grip rather than just power grip
Species: Homosapien
 8. Teeth and Jaws
 Teeth and jaws much smaller in humans than apes
 Canines about same size in males and females of
humans
 Canines significantly larger in males than females of
apes
 Bowl shaped dental arcade in humans compared to the
U shape in apes
 No diastema in humans
Species: Homosapien
 9. Brain
 HUGE
 Cortex of Cerebrum is folded lots giving more volume
and surface area
 Gives reasoning, maths, language, artistic skills, abstract
thought, imagination, perception of senses
 Cerebellum is large giving good balance and muscular co
ordination
Species: Homosapien
 Speech
 Development of Broca’s area giving the ability to
organise sounds into meaningful sentences
 Wernicke’s Area is well developed giving the ability to
interpret the sounds heard
Questions…
 1. Discuss the importance of diet in the evolution of the
primate brain (E)
 2. To which class of vertebrates to primates belong?
 3. Three important characteristics of primates that have
contributed to their success are; Grasping hands, Well
developed vision and Highly developed vocal
communication.
Explain why each of these characteristics is important for
arboreal life (M)
 4. Ape and human hips, legs and feet differ frome ach
other. Explain how one of these would differ between apes
and humans and why it is different. Relate this to
locomotion (M)
 5.
Australopithecines to Homo’s =]
(Different genus’s!)
Genus: Australopithecines
 (Bipedal, Brain significantly smaller but bigger than a chimp, Canines
reduced and non protruding, Shorter, Large degree of sexual dimorphism,
No evidence of stone tools but perhaps stick tools, Now extinct)
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Earliest known pre-humans
Fossil record of 4 million to 1 million years ago
9 species within this genus
Fossils found in Africa, mostly in the East African Rift
Valley
 This is an area where two tectonic plates are moving apart
and volcanic activity caused the burial and fossilisation of
animals including pre humans
Genus: Australopithecines
 Fossils show that bipedalism preceded brain expansion
 Giving more freedom to the hands, bipedalism paved
the way for intellectual activities such as tool making
 According to teeth and skull anatomy,
Australopithecines can be seen as Robust or Gracile
(slender)
 Robust types are thought to be specialised herbivores
and evolutionary side branches
 Most became extinct and did not lead to humans but
side branches of the evolutionary tree
Australopithecines Africanus
 Sum up and write down what you call tell about this
species by your evolutionary tree….
 Forward foramen magnum therefore considered to be
bipedal
 Small canines, parabolic tooth row, less protruding
jaw, lack of simian shelf, and lack of diastema
Australopithecines Africanus
Australopithecus Afarensis
 Sum up and write down what you call tell about this species
by your evolutionary tree….
 LUCY!!
 Bipedal due to features of the knee, hip, big toe and valgus
angle
 Primate like (primitive) due to
 Strong sexual dimorphism
 Small brain
 Large canines
 Parallel side tooth rows
 Slightly curves and longer phalanges
Australopithecus Afarensis
Australopithecus Robustus and
Australopithecus Boisei
 Sum up and write down what you call tell about this
species by your evolutionary tree….
 Both seen as ‘robust species’
 Different to A. Africanus and A. Afarensis due to
 Huge flat molars (herbivores)
 But smaller incisors and canines
 Prominent sagittal crest*
 Wide cheek bones (zygomatic arches)*
 * Suggests massive temporal muscle to raise the lower
jaw powerfully
Australopithecus Robustus and
Australopithecus Boisei continued..
 Huge molars and jaw muscles, as well as small incisors
and canines suggests…. (pg. 396 Study Guide)
Australopithecus Robustus (South
Africa) and Australopithecus Boisei
(East Africa) continued..
Ardipithecus Ramidus
 Sum up and write down
what you call tell about
this species by your
evolutionary tree….
 Forward foramen
magnum suggesting
bipedalism
 Relatively large canines
 Longer arm bones than
A. Afarensis
Australopithecus Anamensis
 Who’s great great great great great Grandad is this?
 Sum up and write down what you call tell about this
species by your evolutionary tree….
 Humerus and tibia that have been found show
bipedalism
 Large canines, thick enamel covering teeth
Australopithecus Anamensis
The Evolution of Bipedalism
 The most important event in human evolution
Fossils and dating
 Fossils are created when an organism that dies is
covered in mud, river sediment or volcanic ash. The
hard parts are replaced by minerals of surrounding
materials (usually sedimentary rock). Older fossils are
found deeper.
How old are the fossils? Dating!
 Absolute dating
 This gives you the date in years (from 10’s of thousands
to 100’s of millions)
 This is done through knowing the rate at which
radioactive isotope decay at.
 The rate of decay is constant and called the half life.
 Commonly carbon 14 and carbon 12 are used to date
wood or bone
 Commonly potassium - argon is used to date rock in
which a fossil is lying which is OLDER than 400,000
years
How old are the fossils? Dating!
 Relative dating
 Tells you the age of a fossil relative to another
 E.g this fossil is older than that one.
 Can do this by measuring the nitrogen/ fluoride ratios
of two bones, the one with less is older as bones lose this
as they get older