Evolutionary trends in homonins

• Species mentioned in the syllabus:

  • Australopithecus afarensis
  • Australopithecus africanus
  • Paranthropus robustus (non-ancestor)
  • Homo habilis
  • Homo erectus
  • Homo neanderthalensis
  • Homo sapiens
• Relative size of the cerebral cortex: (in homonins)

  • gradual increase is an evolutionary trend
  • endocasts used to calculate cranial capacity and number of convolutions
  • early homonins had a cranium size closer to modern apes than modern humans
  • as brain case expanded, the face flattened and a noticeable forehead began to develop
• Prognathism and dentition: (in homonins)

  • Australopithecus afarensis had a lower jaw and face alike other apes, large teeth and distinct gap between canines and incisors
  • Homo habilis had smaller and narrower molars