Hominid studies:
Evidence that primates have common ancestor;
• Biogeographical evidence
• Primates have characteristics that are adaptation to arboreal way of life:
- Clavicle (collarbone) still present (supports hanging weight)
- long, slender limbs - rotate freely at shoulders & hips
- Mobile opposable thumbs - grasp & hold things
• Other characteristics all primates share:
- Enlarged & complex brain
- Forward-facing eyes
- Flat nails
- Low and rounded cusps on molar teeth
- Complex social behaviour (one offspring cared well for)
• Genetic evidence of common ancestor:
- Primates share 98,5% of DNA with chimpanzees and 93% with rhesus monkeys (therefore had
common ancestor at some stage)
- Have larger number of olfactory pseudo-receptor genes than non-primates (remnants of genes
that are no longer functional)
- Have full trichromatic colour vision (only found in primate order)
Sequence of human evolution:
• Humans belong to order primates. Divided into:
- Prosimians (lower primates eg. lemur, galago)
- Hominoidea eg. monkeys, african apes, humans (gave rise to hominidae family)
NOTE: Humans split from chimps 6 m.y.a
,Anthropoids (higher primates):
• Hominoids (great apes)
- Humans
- Chimpanzee
- Gorilla
- Orangutan
• Old & New world monkeys:
- Gibbon
- Baboon
- Monkey
Prosimians (lower primates):
- Tarsier
- Lemur
- Galago
Evidence for common ancestor for living hominids:
• Physical and genetic similarities shoe that homo sapiens closely resemble African Apes
• NB: Humans did not evolve from apes; the 2 groups evolved from a common ancestor 6 m.y.a
• Anatomical similarities:
- Upright posture
- Lack external tails
- Have freely rotating arms
- Have hands with opposable thumbs
- Flat nails
- Forward-facing eyes
- Low and rounded moalr cusps
- Colour vision
, - Sexually dimorphic
• Anatomical differences:
- Skeletal differences:
Apes have: Humans have:
~ Arms longer than legs ~ Arms shorter than legs
~ Long, curves fingers & toes ~ Short, straight fingers & toes
~ Divergent big toes ~ Thumbs can grasp objects
~ Large, elongated hipbones ~ Short, broad pelvis
~ Bow-shaped spine (c-curved) ~ Longer femurs, set further apart at hips (slanted)
~ Feet have strong heel, convergent big toe
~ S-curved spine
- Brain differences:
~ Human brain: 1400 cc
~ Chimp brain; 395 cc
~ Human hands have more dexterity
~ Humans used and controlled fire
~ Humans used developed language
- Skull differences:
~ Humans don't have brow ridge
~ Foramen magnum is located under human skull, unlike ape skulls where it is at the rear (cause
of bipedalism in humans)
~ Humans have large brain case, small jaw. Apes have the opposite
~ Humans have small canine teeth. Apes have large and pointed canines & diastema (space for
canines to overlap other teeth)
Evidence that primates have common ancestor;
• Biogeographical evidence
• Primates have characteristics that are adaptation to arboreal way of life:
- Clavicle (collarbone) still present (supports hanging weight)
- long, slender limbs - rotate freely at shoulders & hips
- Mobile opposable thumbs - grasp & hold things
• Other characteristics all primates share:
- Enlarged & complex brain
- Forward-facing eyes
- Flat nails
- Low and rounded cusps on molar teeth
- Complex social behaviour (one offspring cared well for)
• Genetic evidence of common ancestor:
- Primates share 98,5% of DNA with chimpanzees and 93% with rhesus monkeys (therefore had
common ancestor at some stage)
- Have larger number of olfactory pseudo-receptor genes than non-primates (remnants of genes
that are no longer functional)
- Have full trichromatic colour vision (only found in primate order)
Sequence of human evolution:
• Humans belong to order primates. Divided into:
- Prosimians (lower primates eg. lemur, galago)
- Hominoidea eg. monkeys, african apes, humans (gave rise to hominidae family)
NOTE: Humans split from chimps 6 m.y.a
,Anthropoids (higher primates):
• Hominoids (great apes)
- Humans
- Chimpanzee
- Gorilla
- Orangutan
• Old & New world monkeys:
- Gibbon
- Baboon
- Monkey
Prosimians (lower primates):
- Tarsier
- Lemur
- Galago
Evidence for common ancestor for living hominids:
• Physical and genetic similarities shoe that homo sapiens closely resemble African Apes
• NB: Humans did not evolve from apes; the 2 groups evolved from a common ancestor 6 m.y.a
• Anatomical similarities:
- Upright posture
- Lack external tails
- Have freely rotating arms
- Have hands with opposable thumbs
- Flat nails
- Forward-facing eyes
- Low and rounded moalr cusps
- Colour vision
, - Sexually dimorphic
• Anatomical differences:
- Skeletal differences:
Apes have: Humans have:
~ Arms longer than legs ~ Arms shorter than legs
~ Long, curves fingers & toes ~ Short, straight fingers & toes
~ Divergent big toes ~ Thumbs can grasp objects
~ Large, elongated hipbones ~ Short, broad pelvis
~ Bow-shaped spine (c-curved) ~ Longer femurs, set further apart at hips (slanted)
~ Feet have strong heel, convergent big toe
~ S-curved spine
- Brain differences:
~ Human brain: 1400 cc
~ Chimp brain; 395 cc
~ Human hands have more dexterity
~ Humans used and controlled fire
~ Humans used developed language
- Skull differences:
~ Humans don't have brow ridge
~ Foramen magnum is located under human skull, unlike ape skulls where it is at the rear (cause
of bipedalism in humans)
~ Humans have large brain case, small jaw. Apes have the opposite
~ Humans have small canine teeth. Apes have large and pointed canines & diastema (space for
canines to overlap other teeth)
