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Phylogenetic rate shifts in feeding time during the evolution of Homo.

Publication ,  Journal Article
Organ, C; Nunn, CL; Machanda, Z; Wrangham, RW
Published in: Proceedings of the National Academy of Sciences of the United States of America
August 2011

Unique among animals, humans eat a diet rich in cooked and nonthermally processed food. The ancestors of modern humans who invented food processing (including cooking) gained critical advantages in survival and fitness through increased caloric intake. However, the time and manner in which food processing became biologically significant are uncertain. Here, we assess the inferred evolutionary consequences of food processing in the human lineage by applying a Bayesian phylogenetic outlier test to a comparative dataset of feeding time in humans and nonhuman primates. We find that modern humans spend an order of magnitude less time feeding than predicted by phylogeny and body mass (4.7% vs. predicted 48% of daily activity). This result suggests that a substantial evolutionary rate change in feeding time occurred along the human branch after the human-chimpanzee split. Along this same branch, Homo erectus shows a marked reduction in molar size that is followed by a gradual, although erratic, decline in H. sapiens. We show that reduction in molar size in early Homo (H. habilis and H. rudolfensis) is explicable by phylogeny and body size alone. By contrast, the change in molar size to H. erectus, H. neanderthalensis, and H. sapiens cannot be explained by the rate of craniodental and body size evolution. Together, our results indicate that the behaviorally driven adaptations of food processing (reduced feeding time and molar size) originated after the evolution of Homo but before or concurrent with the evolution of H. erectus, which was around 1.9 Mya.

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Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

August 2011

Volume

108

Issue

35

Start / End Page

14555 / 14559

Related Subject Headings

  • Phylogeny
  • Humans
  • Hominidae
  • Feeding Behavior
  • Body Size
  • Biological Evolution
  • Animals
 

Citation

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Organ, C., Nunn, C. L., Machanda, Z., & Wrangham, R. W. (2011). Phylogenetic rate shifts in feeding time during the evolution of Homo. Proceedings of the National Academy of Sciences of the United States of America, 108(35), 14555–14559. https://doi.org/10.1073/pnas.1107806108
Organ, Chris, Charles L. Nunn, Zarin Machanda, and Richard W. Wrangham. “Phylogenetic rate shifts in feeding time during the evolution of Homo.Proceedings of the National Academy of Sciences of the United States of America 108, no. 35 (August 2011): 14555–59. https://doi.org/10.1073/pnas.1107806108.
Organ C, Nunn CL, Machanda Z, Wrangham RW. Phylogenetic rate shifts in feeding time during the evolution of Homo. Proceedings of the National Academy of Sciences of the United States of America. 2011 Aug;108(35):14555–9.
Organ, Chris, et al. “Phylogenetic rate shifts in feeding time during the evolution of Homo.Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 35, Aug. 2011, pp. 14555–59. Epmc, doi:10.1073/pnas.1107806108.
Organ C, Nunn CL, Machanda Z, Wrangham RW. Phylogenetic rate shifts in feeding time during the evolution of Homo. Proceedings of the National Academy of Sciences of the United States of America. 2011 Aug;108(35):14555–14559.
Journal cover image

Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

August 2011

Volume

108

Issue

35

Start / End Page

14555 / 14559

Related Subject Headings

  • Phylogeny
  • Humans
  • Hominidae
  • Feeding Behavior
  • Body Size
  • Biological Evolution
  • Animals