Diet and the evolution of the earliest human ancestors.

Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 01/2001; 97(25):13506-11. DOI: 10.1073/pnas.260368897
Source: PubMed

ABSTRACT Over the past decade, discussions of the evolution of the earliest human ancestors have focused on the locomotion of the australopithecines. Recent discoveries in a broad range of disciplines have raised important questions about the influence of ecological factors in early human evolution. Here we trace the cranial and dental traits of the early australopithecines through time, to show that between 4.4 million and 2.3 million years ago, the dietary capabilities of the earliest hominids changed dramatically, leaving them well suited for life in a variety of habitats and able to cope with significant changes in resource availability associated with long-term and short-term climatic fluctuations.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Classic life-history theory predicts that menopause should not occur because there should be no selection for survival after the cessation of reproduction [1]. Yet, human females routinely live 30 years after they have stopped reproducing [2]. Only two other species-killer whales (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) [3, 4]-have comparable postreproductive lifespans. In theory, menopause can evolve via inclusive fitness benefits [5, 6], but the mechanisms by which postreproductive females help their kin remain enigmatic. One hypothesis is that postreproductive females act as repositories of ecological knowledge and thereby buffer kin against environmental hardships [7, 8]. We provide the first test of this hypothesis using a unique long-term dataset on wild resident killer whales. We show three key results. First, postreproductively aged females lead groups during collective movement in salmon foraging grounds. Second, leadership by postreproductively aged females is especially prominent in difficult years when salmon abundance is low. This finding is critical because salmon abundance drives both mortality and reproductive success in resident killer whales [9, 10]. Third, females are more likely to lead their sons than they are to lead their daughters, supporting predictions of recent models [5] of the evolution of menopause based on kinship dynamics. Our results show that postreproductive females may boost the fitness of kin through the transfer of ecological knowledge. The value gained from the wisdom of elders can help explain why female resident killer whales and humans continue to live long after they have stopped reproducing. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
    Current Biology 03/2015; DOI:10.1016/j.cub.2015.01.037 · 9.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Au. anamensis es un hominino del Plio-Pleistoceno que habitó en un rango amplio de ambientes, que incluía ambientes cerrados y zonas más abiertas de sabana. El análisis de su patrón de microestriación vestibular (n=5) muestra una abrasividad superior (NT=220,60) al de Au. afarensis (NT: 150,69). En cambio, el patrón de Au. anamen-sis muestra claras afinidades con el de varias especies cercopitecoi-deas como Cercocebus , Mandrillus y Cercopithecus sp., tanto para el número total de estrías como en un análisis discriminante. Estos re-sultados indican que Au. anamensis presentaba un régimen alimen-tario de tipo frugívoro-granívoro similar al de los cercopitécidos ac-tuales (semillas, nueces, rizomas, tubérculos, raíces), a diferencia de Au. afarensis, una especie eminentemente frugívora.
    Biodiversidad Humana y Evolución, Edited by Daniel Turbón, Lourdes Fañanás, Carme Rissech, Araceli Rosa, 01/2011: pages 450-454; Universitat de BArcelona, SEAF, Fundació Uriach 1938 and Ministerio de Economía y Competitividad., ISBN: 978-84-695-6323-6
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cercopithecoides williamsi, a Plio-Pleistocene primate, is believed to have been a terrestrial colobine monkey. Dental microwear analysis of C. williamsi specimens from South African cave sites was employed to test these assumptions. Analysis of the features shows that although the microwear signature of C. williamsi is similar to that of folivorous primates, there are also similarities with terrestrial papionins. Overall, the dental microwear analysis demonstrates that C. williamsi could have indeed been a folivorous, terrestrial monkey. A high amount of puncture pits also points to a substantial amount of grit in the diet. Similarities between the microwear features of C. williamsi and Cebus apella indicate that fruit or hard objects could have been a supplemental food of C. williamsi. The consumption of underground storage organs covered in grit would explain the heavy pitting of C. williamsi teeth. Being terrestrial, C. williamsi would have been in direct competition with terrestrial papionins.
    04/2013, Degree: Master of Arts, Supervisor: Frank L'Engle Williams

Full-text (2 Sources)

Available from
May 21, 2014