91606 - Human Evolution

mandible

lower jaw

prognathism

protusion of lower face (‘snout-like’)

chimpanzee cranial capacity

400-500 cc

human cranial capacity

1400 cc

human pharynx

longer/large - more sounds

chimpanzee pharynx

shorter - less sounds

human jaw shape

V

chimpanzee jaw shape

U

diastema

gap between teeh for canines to fit in the jaw

human canines

smaller for softer food

chimpanzee canines

large for aggressive displays, not meat

human zygomatic arch

smaller for less support for jaw muscles - softer food

chimpanzee zygomatic arch

larger for more jaw support - hard fibrous plant foods

H sagittal crest

very small - less jaw support needed

C sagittal crest

large - more jaw support needed

nuchal crest

extension of skull to which neck muscles attach

H nuchal crest

smaller - less support required for neck - bipedal

C nuchal crest

larger - more neck support required - quadruped

frontal lobe

provides ability for abstract and logical thought, imagination, complex language, and artistic ability

H frontal lobe

large, so large forehead

C frontal lobe

small - no forehead

Wernicke’s area

humans - receives sensory inputs and is responsible for language comprehension

Broca’s region

H - coordinates muscular movements required to produce speech