Now showing items 41-60 of 182

    • A Direct Comparison of Scan and Focal Sampling Methods for Measuring Wild Chimpanzee Feeding Behaviour 

      Gilby, Ian C.; Pokempner, Amy; Wrangham, Richard W. (Karger, 2010)
      Focal sampling is the most accurate method for measuring primate activity budgets, but is sometimes impractical. An alternative is scan sampling, in which the behaviour of the group is recorded at regular intervals. The ...
    • Distribution of a Chimpanzee Social Custom Is Explained by Matrilineal Relationship Rather Than Conformity 

      Wrangham, Richard W.; Koops, Kathelijne; Machanda, Zarin Pearl; Worthington, Steven; Bernard, Andrew B.; Brazeau, Nicholas F.; Donovan, Ronan; Rosen, Jeremiah; Wilke, Claudia; Otali, Emily; Muller, Martin N. (Elsevier BV, 2016)
      High-arm grooming is a form of chimpanzee grooming in which two individuals mutually groom while each raising one arm. Palm-to-palm clasping (PPC) is a distinct style of high-arm grooming in which the grooming partners ...
    • Do Transmission Mechanisms or Social Systems Drive Cultural Dynamics in Socially Structured Populations? 

      Nunn, Charles Lindsay; Thrall, Peter H.; Bartz, Kevin; Dasgupta, Tirthankar; Boesch, Christophe (Elsevier, 2009)
      Cultural traits spread via multiple mechanisms among individuals within social groups, including via transmission biases that occur when subordinates copy from dominants (prestige transmission), or via common cultural trait ...
    • Does Sleep Play a Role in Memory Consolidation? A Comparative Test 

      Capellini, Isabella; McNamara, Patrick; Preston, Brian T.; Nunn, Charles; Barton, Robert A. (Public Library of Science, 2009)
      Sleep is a pervasive characteristic of mammalian species, yet its purpose remains obscure. It is often proposed that ‘sleep is for the brain’, a view that is supported by experimental studies showing that sleep improves ...
    • The Dynamics of Stress in Female Chimpanzees: Interactions of Social and Ecological Factors 

      Thompson, Melissa Emery; Kahlenberg, Sonya M.; Muller, Martin N.; Wrangham, Richard (John Wiley & Sons, 2009)
      Cortisol, as a biomarker of the generalized adaptive stress response, can provide critical information on the physiological effects of behavior. However, group-living animals face multiple interacting stressors from their ...
    • The effect of a "bent-knee" gait on trabecular orientation: an experiment test of Wolff's Law 

      Pontzer, Herman; Lieberman, Daniel; Momin, E.N.; Devlin, Maureen J.; Polk, John D.; Hallgrimsson, Benedikt; Cooper, David M.L. (John Wiley & Sons, 2005)
      While recent attempts have been made to link trabecular orientation to gait and posture in extinct hominids, there have been few controlled experiments to test the hypothesis that there is a predictable functional relationship ...
    • The Effects of Food Processing on Masticatory Performance and Its Implications for Hominid Cranio-dental Evolution 

      Duncan, Katherine; Lieberman, Daniel (John Wiley & Sons, 2007)
      A steady decrease in relative dental and facial size occurred during the evolution of the genus Homo. It is often hypothesized that this reduction was made possible by, or was an adaptation for chewing food that was cooked ...
    • Effects of the Distribution of Female Primates on the Number of Males 

      Carnes, Laurel Mariah; Nunn, Charles Lindsay; Lewis, Rebecca J. (Public Library of Science, 2011)
      The spatiotemporal distribution of females is thought to drive variation in mating systems, and hence plays a central role in understanding animal behavior, ecology and evolution. Previous research has focused on investigating ...
    • Enamel thickness in Asian human canines and premolars 

      FEENEY, ROBIN N.M.; ZERMENO, JOHN P.; REID, DONALD J.; NAKASHIMA, SYOZI; SANO, HIROSHI; BAHAR, ARMASASTRA; HUBLIN, JEAN-JACQUES; Smith, Tanya (Anthropological Society of Nippon, 2010)
      Dental enamel thickness continues to feature prominently in anthropological studies of ape and human evolution, as well as studies of preventative oral care and treatment. Traditional studies of enamel thickness require ...
    • Enamel Thickness in Bornean and Sumatran Orangutan Dentitions 

      Smith, Tanya; Kupczik, Kornelius; Machanda, Zarin Pearl; Skinner, Matthew M.; Zermeno, John P. (Wiley, 2012)
      Dental enamel thickness has received considerable attention in ecological models of the adaptive significance of primate morphology. Several authors have theorized that the degree of enamel thickness may reflect selective ...
    • Energetic Consequences of Thermal and Non-Thermal Food Processing 

      Carmody, Rachel Naomi (2013-03-06)
      All human societies process their food extensively by thermal and non-thermal means. This feature distinguishes us from other species, and may even be compulsory given that humans are biologically committed to an energy-rich ...
    • Energetic Costs of Reproductive Effort in Male Chimpanzees 

      Georgiev, Alexander (2012-09-14)
      Male reproductive success in many mammals depends on their ability to allocate sufficient energetic resources to mating competition. Such costs are particularly pronounced in species with high levels of sexual body dimorphism, ...
    • The Energetic Significance of Cooking 

      Carmody, Rachel Naomi; Wrangham, Richard W. (Wiley-Blackwell, 2009)
      While cooking has long been argued to improve the diet, the nature of the improvement has not been well defined. As a result, the evolutionary significance of cooking has variously been proposed as being substantial or ...
    • Energetics, Reproductive Ecology, and Human Evolution 

      Ellison, Peter (Paleoanthropology Society / University of Pennsylvania Museum of Archaeology and Anthropology, 2008)
      Human reproductive ecology is a relatively new subfield of human evolutionary biology focusing on the responsiveness of the human reproductive system to ecological variables. Many of the advances in human, and more recently ...
    • Energy Pooling and Implications for the Unique Traits of the Human Life History Strategy 

      Sharrock, Katherine C.; Reiches, Meredith W.; Lipson, Susan F.; Kramer, Karen L.; Ellison, Peter (John Wiley & Sons, 2009)
      Compared to non-human primates, human life history is characterized by slow juvenile growth, late age at maturity, short interbirth intervals, and a decoupling of reproductive senescence and somatic senescence. Some of ...
    • Entwined African and Asian Genetic Roots of Medieval Peoples of the Swahili Coast 

      Brielle, Esther; Fleisher, Jeffrey; Wynne-Jones, Stephanie; Sirak, Kendra; Broomandkhoshbacht, Nasreen; Callan, Kimberly; Curtis, Elizabeth; Iliev, Lora; Lawson, Ann; Oppenheimer, Jonas; Qiu, Lijun; Stewardson, Kristin; Workman, James; Zalzala, Fatma; Ayodo, George; Gidna, Agness; Kabiru, Angela; Kwekason, Amandus; Mabulla, Audax Z. P.; Manthi, Fredrick; Ndiema, Emmanuel; Ogola, Christine; Sawchuk, Elizabeth; Al-Gazali, Lihadh; Ali, Bassam; Ben-Salem, Salem; Letellier, Thierry; Pierron, Denis; Radimilahy, Chantal; Rakotoarisoa, Jean-Aimé; Raaum, Ryan L.; Culleton, Brendan J.; Mallick, Swapan; Rohland-Pinello, Nadin; Patterson, Nick; Mwenje, Mohammed Ali; Ahmed, Khalfan Bini; Mohamed, Mohamed Mchulla; Williams, Sloan R.; Monge, Janet M.; Kusimba, Sibel; Prendergast, Mary; Reich, David; Kusimba, Chapurukha (SpringerNature, 2023-03-29)
      The urban peoples of the Swahili coast traded across eastern Africa and the Indian Ocean and were among the first sub-Saharan practitioners of Islam [1, 2]. The extent to which these early interactions between Africans and ...
    • The Epigenetic Funnel and the Cranial Base: How Cranial Bone Growth Helps Integrate Interactions between the Face and the Brain to Constrain Overall Skull Shape 

      Lieberman, Daniel; Hallgrimsson, Benedikt; Liu, W. (John Wiley & Sons, 2007)
      Understanding the developmental and genetic bases for evolutionarily important variations in complex phenotypes such as the skull is a challenge because of the complexity of the factors involved. We hypothesize that even ...
    • Equal, Similar, but Different: Convergent Bonobos and Conserved Chimpanzees 

      Hare, Brian; Wrangham, Richard (Harvard University Press, 2017-12-31)
      A critical goal for human evolutionary biology is understanding when and how traits evolved in our ancestral lineage during the 6.5-9.3 million years since our split with the ancestors of chimpanzees and bonobos. Comparisons ...
    • Estradiol, estrogen receptor alpha, and osteogenic responses to mechanical loading 

      Devlin, Maureen J.; Lieberman, Daniel; Olsen, Bjorn R.; Fukai, Naomi (John Wiley & Sons, 2005)
      Despite evidence that mechanical loads can induce diaphyseal bone growth, there is little consensus about how, and to what extent, strain affects human skeletal phenotype. This project tests a mechanism of mechanotransduction ...
    • Evidence for a Trade-Off Strategy in Stone Oak (Lithocarpus) Seeds between Physical and Chemical Defense Highlights Fiber as an Important Antifeedant 

      Chen, Xi; Cannon, Charles H.; Conklin-Brittain, Nancy Lou (Public Library of Science, 2012)
      Trees in the beech or oak family (Fagaceae) have a mutualistic relationship with scatter-hoarding rodents. Rodents obtain nutrients and energy by consuming seeds, while providing seed dispersal for the tree by allowing ...