Human Biology: Human Evolution

Ardipithecus group: Sahelanthropus Tchadensis

• (7-6 mya)

• Thicker enamel

• Reduced prognathism

• Massive brow ridge

• Foramamen magnum under skull

• Brain 320-380cc

• chad

Ardipithecus group: Orrorin tugenensis

(- 6mya)

• Kenya

• Between chimp and human

• Chimp-like front teeth

• Slight diastema

• Human like molars

Ardipithecus group: Ardipithecus ramidur

• Ethiopia

• Rigid-like foot

• Grasping toe

• Ooodland dwelling

• Limb proportion similar to quadrupedal Miocene apes

Australopithecus Group

• erect and bipedal

• Relatively long forelimb (ape-like)

• Sexually dimorphic

• Small brains

• Intermediateteeth

• - slight diastea

• Reduced canine dimorphism

• Large molars

• Thicker enamel than ape

• Cranial capacity: 400-450cc

Locomotory transition: Arboreal suspnsory to bipedal (3.8 mya)

• Australopithecus: warming, drying climate → forest to Savannah woodland.

• 1. Postural adaption for feeding

• 2. Thermoregatory (reduce surface area for insulation)

• 3. Energetic of movement over open ground.

• Carrying objects

• Wading hypothesis

Australopithecus afernsis (4.2-2.9 mya)

• Lucy - Adult female

• Sex dimorphism

• Skull/dentition

• Small brain case

• Prognathism

• Reduced canine

• Little bit of a diastema

• Early bipedal, but arms are somewhat longer relative to legs than in humans → slept and foraged in trees

Australopithecus africanus

• South Africa

• Southern ape of African

• Small brain case

• Reduced canines

Earliest Homo: H.habilis and H.rudolfensis

• East Africa

• Bipedal

• Forelimbs proportions similar to A.afarensis. (Arms somewhat longer relative to legs than in humans

• Reduced facial size and small teeth; monomorphic canines: smaller molars; thinner enamel

• Slightly enlarged brain

• Cranial capacity: 700c

• Tools: Oldowan stone

Chimp (Pan)

• Quadrupedal

• 1st molar eruption (yrs): 3-3.5

• Dimorphism canines’ thin enamel Slightly enlarged

• Cranial capacity: 400cc

• Tools: few

Homo ergaster And H. erectus

- H.ergaster in Africa: form 2.0 - 0.6 mya

• Mostly acheulian tools

• Controlled fire

• Hunting of large mammals

• Some diver from Africa to early Eurasia + Asia

• Cranial capacity: 840 (some say 1000)

  H. Erects in Asia approx 1.8-0.1 mya

• Less complex tools than H. Ergaster

• Controlled fire

• Dead end group but persists longer than H. Ergaster

• Cranial capacity: 840 ( some say 1000 cc)

• Body mass: 60kg

H. Heidelbergensis

• 800-200 kya

• Bipedal

• Unknown fist molar eruption

• Body mass: 80(?) large

• Cranial capacity: 1200cc to 1300cc

• Tools: Acheulian: hunt big game.

H. Sapiens

• bipedal

• First molar eruption: 6 years

• Body mass: 60kg

• Cranial capacity: 1250-1400cc

• Tools: paleolithic complexes

H. Neanderthalensis

• 400000- 40000 ya

• Cranial capacity: 1500cc