Human Evolution

, Volume 4, Issue 1, pp 33–44

Early hominid physical evolution

  • Lia Queiroz do Amaral

DOI: 10.1007/BF02436417

Cite this article as:
do Amaral, L.Q. Hum. Evol. (1989) 4: 33. doi:10.1007/BF02436417


Hindrances against bipedalism evolution are localized in obstetrical constraints, maternal mortality rates, infant birth trauma and unsafe pregnancy. Analysis of infant survival probability shows that a shift to bipedalism could occur as a necessary consequence of the process of body fur reduction, in a balance between such hindrances and safe infant transportation. Fur reduction is proposed to correlate with cooling mechanism in intra-species physical fights. The triggering of a feed-back mechanism connecting reduction of body fur to canine reduction would be responsible for a passage from threat displays to actual physical fights. The proposed scenario for such changes is the transition from uni-male to multi-male social structures among Hominoidea. The implications of the approach adopted are discussed.

Key words

bipedalismreproductionloss of furinfant carryingcanine reduction

Copyright information

© Editrice Il Sedicesimo 1989

Authors and Affiliations

  • Lia Queiroz do Amaral
    • 1
  1. 1.Instituto de FisicaUniversidade de São PauloSão PauloBrasil