Evolutionary Trends

Question 1

Describe Australopithecus (Afarensis & Africans)

Answer 1

Age Range: 3.6 million years ago
Digits: Opposable thumb however less mobile, bigger and heavier fingers (powerful grasp)
Dentition & Prognathism: projecting jaw (ape like), large canines, thick molars and pre molars, vegetarian diet
Skull: 450cm, low forehead, NO saggital crest, skull more rounded
Foramen Magnum: more forward for erect posture
Spinal curve: S shaped, double curvature
Pelvis: more human like - bowl shaped, broader, shorter
Knee/carrying angle, centre of gravity: femur angled like humans, carrying angle evident
Foot: heel hitting ground first - heel –> ball weight distribution, longitudinal arch present , non opposable big, non prehensile

Question 2

Describe Australopithecus Paranthropus Robustus

Answer 2

Age Range: 1.2 million years ago, HEAVY BUILD
Digits: Greater precision grip, very powerful grasp
Dentition & Prognathism: bigger molars, low forehead, , large jaw attached to skull by powerful chewing muscle s
Skull: 542cm, SAGGITAL CREST
Foramen Magnum: More forward for erect posture
Spinal Curve: S shaped curve, double curvature
Pelvis: more human like
Knee, carrying angle, centre of gravity: femur angled like human, carrying angle evident
Foot: heel hitting ground first - heel –> ball weight distribution, longitudinal arch present, strong non prehensile big toe

Question 3

Describe Homo Habilis

Answer 3

Age Range: 1.75 million years ago, first user of tools (oldwan tools)
Digits: Greater precision grip, still had powerful grasp
Dentition & Prognathism: teeth were smaller, still slightly larger canines, flat nose and brow ridge
Skull: 590cm, NO SAGGITAL CREST, larger brain - increased awareness of surroundings, increased dev in frontal lobe
Foramen Magnum: more of skill behind fm
Spinal Curve: S shaped, double curvature
Knee, carrying angle, centre of gravity: stood more erect, carrying angle present
Foot: strong non prehensile big toe, shorter toes like humans,longutudinal arch

Question 4

Describe Homo Erectus

Answer 4

Age Range: 1.5 million - 200 000 years ago** First to leave Africa, USED FIRE –> MEAT EATERS
Digits: greater precision grip, still powerful grasp
Prognathism: flatter face due to expansion of brain, smaller teeth, decreased jaw size
Skull: 1000cm, increased convolutions, increased frontal lobe, no chin, OCCIPITAL ROUNDED BUN
Foramen magnum: more foward
Spinal Curve: S shaped
Knee, carrying angel, centre of gravity: stood more erect
Foot: strong non prehensile big toe, shorter toes like humans,longutudinal arch

Question 5

Describe Homo Neanderthalensis

Answer 5

Age range: 250 000 - 30 000 years ago, survived the ice age
Digits: greater precision grip, still powerful grasp
Dentition & Prognathism: rounded skull, NOSE PROJECTED (thought to be due to environmental conditions), larger teeth
Skull: 1485cm, larger brain size than humans, OCCIPITAL ROUNDED BUN, lacked a definite chin, low but large skull, more prominent forehead
Foramen Magnum: more forward
Spinal Curve: S shaped double curvature
Pelvis: Bowl shaped, broader, shorter
Knee, carrying angle, centre of gravity: centre of gravity falls in front of the knee for erect posture and striding gait
Foot: Larger calcaneus bone, well developed longitudinal arch

Question 6

Describe Homo Sapiens

Answer 6

Age Range: 100 000 years ago
Digits: only opposable big thumb, greater precision grip (well developed), decrease power in grip
Dentition & Prognathism: Flatter facial profile, size of jaw is smaller, smaller teeth, canines do not project, jaw is parabola shaped, shorter snout and nose
Skull: 1350cm, rounded, NO SAGGITAL CREST OR OCCIPITAL ROUNDED BUN, increased convolutions and increased size of cerebral cortex, increased developed in frontal lobe, DEVELOPED CHIN
Foramen magnum: located centrally under the skull, no need for large neck ,muscles as weight is borne by the vertebral column under centre of gravity
Spinal Curve: Double curvature - S shaped, lumbar vertebrae wedged shaped making a forward jutting curve
Pelvis: Broader, shorter, bowl shaped to support abdominal organs
Knee, centre of gravity and carrying angle: large head of femur fits into Acetabulum, carrying angle - femur angled towards knee, weight distribution from femur at acetabulum via outer part of femur to outer knee hinge joint, centre of gravity falls in front of the knee, centre of gravity further up (pelvis) for erect posture
Foot: lost prehensility, non opposable big toe, big toe aligned alongside others, longitudinal arch TRANSVERSE ARCH, larger calcaneus and talus bones