Metabolic hypothesis for human altriciality.

Published

Journal Article

The classic anthropological hypothesis known as the "obstetrical dilemma" is a well-known explanation for human altriciality, a condition that has significant implications for human social and behavioral evolution. The hypothesis holds that antagonistic selection for a large neonatal brain and a narrow, bipedal-adapted birth canal poses a problem for childbirth; the hominin "solution" is to truncate gestation, resulting in an altricial neonate. This explanation for human altriciality based on pelvic constraints persists despite data linking human life history to that of other species. Here, we present evidence that challenges the importance of pelvic morphology and mechanics in the evolution of human gestation and altriciality. Instead, our analyses suggest that limits to maternal metabolism are the primary constraints on human gestation length and fetal growth. Although pelvic remodeling and encephalization during hominin evolution contributed to the present parturitional difficulty, there is little evidence that pelvic constraints have altered the timing of birth.

Full Text

Duke Authors

Cited Authors

  • Dunsworth, HM; Warrener, AG; Deacon, T; Ellison, PT; Pontzer, H

Published Date

  • September 2012

Published In

Volume / Issue

  • 109 / 38

Start / End Page

  • 15212 - 15216

PubMed ID

  • 22932870

Pubmed Central ID

  • 22932870

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1205282109

Language

  • eng