Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences

Primates

Institution
Publication Year
Publication
Publication Type

Articles 1 - 30 of 43

Full-Text Articles in Life Sciences

A Conservation Model: Costa Rican Conservation Strategies Effectively Preserve Their Threatened Primates, Ryan Belmont Jan 2024

A Conservation Model: Costa Rican Conservation Strategies Effectively Preserve Their Threatened Primates, Ryan Belmont

Regis University Student Publications (comprehensive collection)

The wildlife of Costa Rica has experienced various anthropogenic threats over the last century including climate change and agricultural expansion. The mantled howler monkey (Alloutta palliata), Central American spider monkey (Ateles geoffroyi), white-faced capuchin (Cebus imitator), and the Central American squirrel monkey (Saimiri oerstedii) are Costa Rica’s native primates that face several anthropogenic threats such as deforestation for agriculture and climate change. In response to increased threats to its four native species of non-human primates, Costa Rica has implemented effective governmental conservation tactics such as the Payments for Environmental Services program, ecotourism …


Understanding The Environmental And Genetic Influence On Fluctuating Asymmetry And Developmental Instability In Primates, Ashly N. Romero Aug 2023

Understanding The Environmental And Genetic Influence On Fluctuating Asymmetry And Developmental Instability In Primates, Ashly N. Romero

Graduate Theses and Dissertations

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation …


Diet And Nutrition Of Lemurs In The Lean Season, Santiago Cassalett Jun 2022

Diet And Nutrition Of Lemurs In The Lean Season, Santiago Cassalett

Dissertations, Theses, and Capstone Projects

Animals must navigate complex food and nutrient environments that are constantly in flux to obtain the macro and micronutrients necessary for their growth, reproduction, and survival. The nutritional needs of animals also vary over the life course, further complicating the search for adequate foods and the nutrients within them. The hypervariable and unpredictable environment of Madagascar creates a complex nutrient landscape for lemurs in particular because they are subject to large fluctuations in food availability. These fluctuations are thought to create extreme periods of nutritional stress during the dry season (known as the lean season) for lemurs. In response, lemurs …


Canine Microwear In Relation To Diet In Sumatran Primates And African Great Apes, Putu Pujiantari Dec 2021

Canine Microwear In Relation To Diet In Sumatran Primates And African Great Apes, Putu Pujiantari

Graduate Theses and Dissertations

This thesis considers canine microwear in relation to diet in five Sumatran primates (Pongo abelii, Hylobates lar, Hylobates agilis, Presbytis thomasi, and Macaca fascicularis) and two African great apes (Pan paniscus and Pan troglodytes schweinfurthii) using both microwear texture analysis and microwear feature analysis techniques. Statistical results for texture analysis show that there are significant differences in scale of maximum and heterogeneity. This indicates that some species have large pits on their canine surfaces, having these dominated by deep features at coarse scale yet have a slight microwear heterogeneity. For feature analysis, all variables show statistically significant variation. Variance in …


Case 3847 – Simopithecus Oswaldi Andrews, 1916 (Currently Theropithecus Oswaldi; Mammalia, Primates, Cercopithecidae), Proposed Conservation By Reversal Of Precedence With Cynocephalus Atlanticus Thomas, 1884., Eric Delson, David M. Alba, Stephen R. Frost, Dagmawit Abebe Getahun, Christopher C. Gilbert Aug 2021

Case 3847 – Simopithecus Oswaldi Andrews, 1916 (Currently Theropithecus Oswaldi; Mammalia, Primates, Cercopithecidae), Proposed Conservation By Reversal Of Precedence With Cynocephalus Atlanticus Thomas, 1884., Eric Delson, David M. Alba, Stephen R. Frost, Dagmawit Abebe Getahun, Christopher C. Gilbert

Publications and Research

The purpose of this application, under Articles 23.9.3 and 81.1 of the Code, is to conserve the usage of the species-group name Simopithecus oswaldi Andrews, 1916 by giving it precedence over its senior subjective synonym Cynocephalus atlanticus Thomas, 1884. Theropithecus is a common to dominant member of the extinct primate community across Africa after 4 million years ago (Jablonski & Frost, 2010) and often co-occurred with extinct humans (Hominini); fossils are also known rarely across Eurasia (Roberts et al., 2014). Most fossil samples are currently included in Theropithecus oswaldi (Andrews, 1916), which is often divided into chrono-geographic subspecies. Cynocephalus atlanticus …


Empathy And Fairness In Nonhuman Primates: Evolutionary Bases Of Human Morality, Colt Halter May 2021

Empathy And Fairness In Nonhuman Primates: Evolutionary Bases Of Human Morality, Colt Halter

Intuition: The BYU Undergraduate Journal of Psychology

Darwin offered an evolutionary perspective on the origins of human morality, suggesting that humans share a biological foundation with nonhuman primates. This paper reviews the current literature on moral and prosocial behaviors of nonhuman primates, specifically examining whether nonhuman primates exhibit behaviors that are typical of empathy and fairness. The literature documents that nonhuman primates exhibit empathetic behaviors regarding emotional contagion and sympathetic concern. There is also evidence that nonhuman primates have a sense of fairness, seen in their reciprocal behaviors and aversion to inequity. Taken together, this suggests that there are evolutionary roots of morality, lending empirical support to …


Effects Of Hierarchical Steepness On Grooming Patterns In Female Tibetan Macaques (Macaca Thibetana), Dong-Po Xia, Xi Wang, Paul A. Garber, Bing-Hua Sun, Lori K. Sheeran, Lixing Sun, Jin-Hua Li Mar 2021

Effects Of Hierarchical Steepness On Grooming Patterns In Female Tibetan Macaques (Macaca Thibetana), Dong-Po Xia, Xi Wang, Paul A. Garber, Bing-Hua Sun, Lori K. Sheeran, Lixing Sun, Jin-Hua Li

Anthropology and Museum Studies Faculty Scholarship

Hierarchical steepness, defined as status asymmetries among conspecifics living in the same group, is not only used as a main characteristic of animal social relationships, but also represents the degree of discrepancy between supply and demand within the framework of biological market theory. During September and December 2011, we studied hierarchical steepness by comparing variation in grooming patterns in two groups of Tibetan macaques (Macaca thibetana), a primate species characterized by a linear dominance hierarchy. Using a focal sampling method, we collected behavioral data from two provisioned, free-ranging groups (YA1 and YA2) at Mt. Huangshan, China. We found …


Effects Of Artificial Enrichment On Western Lowland Gorilla (Gorilla Gorilla Gorilla) Activity Budgets, Angela Perretti Jan 2021

Effects Of Artificial Enrichment On Western Lowland Gorilla (Gorilla Gorilla Gorilla) Activity Budgets, Angela Perretti

West Chester University Master’s Theses

The benefits of enrichment and proper husbandry protocols and their applicability in wildlife research have been important topics of zoological research. Examining activity budgets of various species throughout zoological facilities reap biological, educational, and conservation benefits. We collected data on the behavioral responses of five western lowland gorillas (Gorilla gorilla gorilla) (1 adult male, 2 adult females, 2 infants/juveniles) to a novel climbing structure in the outdoor enclosure at the Philadelphia Zoo. Over a period of 53 nonconsecutive months, we conducted 30-minute focals with 2-minute scan samples on the gorillas (488 total observation hours). We recorded the frequency of …


Population Status, Threats, And Conservation Of Preuss's Red Colobus (Piliocolobus Preussi) And Other Diurnal Primates In The Ndokbou Forest, Littoral Region, Cameroon, Ruth Bowers-Sword Aug 2020

Population Status, Threats, And Conservation Of Preuss's Red Colobus (Piliocolobus Preussi) And Other Diurnal Primates In The Ndokbou Forest, Littoral Region, Cameroon, Ruth Bowers-Sword

Masters Theses, 2020-current

The Ebo-Makombe-Ndokbou forest block in southwest Cameroon lies within the Gulf of Guinea biodiversity hotspot, characterized by extremely high levels of species richness and endemism, including those of primates. These forests may contain one of the last populations of the Critically Endangered Preuss’s red colobus monkey (Piliocolobus preussi; PRC), which is found only in southeastern Nigeria and western Cameroon. Gun hunting for bushmeat and habitat loss and degradation from logging and agriculture are the main threats to PRC. The conservation status of PRC and other primates in the Ndokbou forest are largely unknown, with most regional research efforts occurring in …


The Functional Morphology Of Ingestion In The Platyrrhine Sclerocarpic Harvesters (Platyrrhini, Primates), Zachary Stoffel Klukkert May 2019

The Functional Morphology Of Ingestion In The Platyrrhine Sclerocarpic Harvesters (Platyrrhini, Primates), Zachary Stoffel Klukkert

Dissertations, Theses, and Capstone Projects

The identification of anatomical correlates of diet and feeding behavior in nonhuman primates is an important area of research in biological anthropology. The morphology of the jaws and teeth reflects the phylogeny and adaptations that distinguish taxa and their different ecological niches. Studying the form-function relationships of jaws and teeth in modern species provides a framework for interpreting the diets of extinct species and for inferring the ecological pressures that may have contributed to the evolutionary diversification of primate craniodental morphology. Previous work on modeling primate jaw mechanics has focused largely on the functional context of a closed jaw. Little …


Non-Human Primates In Medical Research And Drug Development: A Critical Review, Jarrod Bailey Mar 2019

Non-Human Primates In Medical Research And Drug Development: A Critical Review, Jarrod Bailey

Jarrod Bailey, PhD

There is much current debate surrounding the use of non-human primates (NHPs) in medical research and drug development. This review, stimulated by calls for evidence from UK-based inquiries into NHP research, takes a critical view in order to provide some important balance against papers supporting NHP research and calling for it to be expanded. We show that there is a paucity of evidence to demonstrate the positive contribution or successful translation of NHP research to human medicine, that there is a great deal of often overlooked data showing NHP research to be irrelevant, unnecessary, even hazardous to human health and …


Climatic Variables Are Strong Predictors Of Allonursing And Communal Nesting In Primates, Alexandra Louppova Feb 2019

Climatic Variables Are Strong Predictors Of Allonursing And Communal Nesting In Primates, Alexandra Louppova

Theses and Dissertations

Allomaternal care (AMC) is widespread throughout the primate order, previous studies have focused on benefits and costs to individuals. However, our understanding of environmental impacts on AMC behaviors in primates is still limited. Our study examines how ecology and environmental factors can predict certain AMC behaviors more than others.


Using Machine Learning To Classify Extant Apes And Interpret The Dental Morphology Of The Chimpanzee-Human Last Common Ancestor, Tesla A. Monson, David W. Armitage, Leslea J. Hlusko Aug 2018

Using Machine Learning To Classify Extant Apes And Interpret The Dental Morphology Of The Chimpanzee-Human Last Common Ancestor, Tesla A. Monson, David W. Armitage, Leslea J. Hlusko

Anthropology Faculty and Staff Publications

Machine learning is a formidable tool for pattern recognition in large datasets. We developed and expanded on these methods, applying machine learning pattern recognition to a problem in paleoanthropology and evolution. For decades, paleontologists have used the chimpanzee as a model for the chimpanzee-human last common ancestor (LCA) because they are our closest living primate relative. Using a large sample of extant and extinct primates, we tested the hypothesis that machine learning methods can accurately classify extant apes based on dental data. We then used this classification tool to observe the affinities between extant apes and Miocene hominoids. We assessed …


Population Genomics Of A Baboon Hybrid Zone In Zambia, Kenneth Lyu Chiou May 2017

Population Genomics Of A Baboon Hybrid Zone In Zambia, Kenneth Lyu Chiou

Arts & Sciences Electronic Theses and Dissertations

Hybridization is increasingly recognized as a common, important process shaping the evolution of organisms including humans. Across hybrid zones, the genomes of incipient species are mixed and recombined through hybridization and backcrossing, creating conditions ideal for evaluating the actions of natural selection on gene variants in novel genomic contexts. This dissertation aims to increase our understanding of hybridization using a Zambian baboon study system in which two species, Kinda baboons (Papio kindae) and grayfoot baboons (Papio griseipes), hybridize despite exhibiting pronounced differences in body size and behavior. Using genome-wide genotypic data prepared using double-digest RADseq, I scan for genomic regions …


Investigating The Genetic Basis For Hominoid Taillessness, Samantha M. Tickey-Mccrane, Holly Dunsworth, Johanna E. Wegener May 2017

Investigating The Genetic Basis For Hominoid Taillessness, Samantha M. Tickey-Mccrane, Holly Dunsworth, Johanna E. Wegener

Senior Honors Projects

Investigating the Genetic Basis for Hominoid Taillessness:

A Comparative Genetic Approach Across Ten Catarrhine Taxa

Samantha Tickey-McCrane1,2, Johanna E. Wegener2, and Holly Dunsworth1

Honors Thesis Abstract Written by Samantha Tickey-McCrane, Departments of Anthropology & Biology

Advisor: Dr. Holly Dunsworth, Department of Anthropology

How did hominoid tail loss occur? My goals are to test phylogenetic and adaptive hypotheses for tail length variation among macaques, and use those insights to reconstruct the evolution of hominoid taillessness. Further, I aim to ultimately uncover which candidate genes or pathways may be responsible for catarrhine tail loss, and what other traits may be affected by …


Choice-Induced Preference: A Challenge For Contrast, Benjamin R. Eisenreich, Benjamin Y. Hayden Jan 2017

Choice-Induced Preference: A Challenge For Contrast, Benjamin R. Eisenreich, Benjamin Y. Hayden

Animal Sentience

In his target article, Zentall asks: “to experience cognitive dissonance is it necessary for one to have conflicting beliefs or even beliefs at all?” He then argues that a simple behavioral process, the Within Trial Contrast Effect, may be sufficient to explain observed cognitive dissonance effects in nonhuman animals and possibly humans as well. We agree with Zentall that this effect is sufficient to explain many reported cognitive dissonance effects in nonhuman animals, but question its sufficiency for primate behavior (both monkeys and humans).


Wild Justice Redux: What We Know About Social Justice In Animals And Why It Matters, Jessica Pierce, Marc Bekoff Sep 2016

Wild Justice Redux: What We Know About Social Justice In Animals And Why It Matters, Jessica Pierce, Marc Bekoff

Marc Bekoff, PhD

Social justice in animals is beginning to attract interest in a broad range of academic disciplines. Justice is an important area of study because it may help explain social dynamics among individuals living in tightly- knit groups, as well as social interactions among individuals who only occasionally meet. In this paper, we provide an overview of what is currently known about social justice in animals and offer an agenda for further research. We provide working definitions of key terms, outline some central research questions, and explore some of the challenges of studying social justice in animals, as well as the …


Capuchins (Cebus Apella) Can Solve A Means-End Problem, Anna M. Yocom, Sarah T. Boysen Aug 2016

Capuchins (Cebus Apella) Can Solve A Means-End Problem, Anna M. Yocom, Sarah T. Boysen

Sarah Boysen, PhD

Three capuchin monkeys (Cebus apella) were tested on a 2-choice discrimination task designed to examine their knowledge of support, modeled after Hauser, Kralik, and Botto-Mahan’s (1999) experiments with tamarins. This task involved a choice between 2 pieces of cloth, including 1 with a food reward placed on its surface, and a second cloth with the food reward next to its surface. After reliably solving the basic problem, the capuchins were tested with various alternations of the original food reward and cloth. The capuchins were able to solve the initial task quickly, and generalize their knowledge to additional functional and nonfunctional …


A Quantitative Genetic Analysis Of Craniofacial Variation In Baboons, Jessica Lynn Joganic May 2016

A Quantitative Genetic Analysis Of Craniofacial Variation In Baboons, Jessica Lynn Joganic

Arts & Sciences Electronic Theses and Dissertations

This dissertation is an explication of baboon craniofacial variation and its genetic basis. Intraspecific variation is the result of input from and complex interactions among genetic information, functional demands, and developmental processes. The relative effect of each of these on craniofacial variation, as well as the degree of inter-trait covariance, determines whether traits can respond to selection and what that response might look like. Using a sample of pedigreed baboons, I quantify craniofacial variation to address specific questions regarding the distribution and magnitude of phenotypic, genetic, and environmental variation patterns. In addition, I identify regions of the genome containing genetic …


Dietary Adaptations And Intra- And Interspecific Variation In Dental Occlusal Shape In Hominin And Non-Hominin Primates, Kelsey O'Neill Jan 2016

Dietary Adaptations And Intra- And Interspecific Variation In Dental Occlusal Shape In Hominin And Non-Hominin Primates, Kelsey O'Neill

Theses and Dissertations

Dental morphology and tooth shape have been used to recreate the

dietary adaptations for extinct species, and thus dental variation can provide

information on the relationship between fossil species and their

paleoenvironments. Variation in living species with known behaviors can provide

a baseline for interpreting morphology, and behavior, in the fossil record.

Tooth occlusal surface outlines in hominins and non-hominin primates, and other

mammals, have been used for assessments of taxonomic significance, with

variability often considered as being primarily phylogenetic. Few studies have

attempted to assess how diet might influence the pattern of variability in closely

related species. Here the …


Interests And Harms In Primate Research, Nathan Nobis Mar 2015

Interests And Harms In Primate Research, Nathan Nobis

Nathan M. Nobis, PhD

The article discusses the moral issues on primate research in reference to the moral defenses by Sughrue and colleagues. It states that Sughrue and colleagues have claimed to provide equal examination of the primate stroke research's ethics. It mentions that the promise to straighten out a number of ethical arguments in favor and against primate research was not fulfilled. Several moral arguments are presented in response to Sughrue and colleagues' moral defense for animal experimentation.


A Longitudinal View Of Primate Life In Two American Laboratories, Jonathan Balcombe May 2014

A Longitudinal View Of Primate Life In Two American Laboratories, Jonathan Balcombe

Experimentation Collection

If representative of other facilities, our findings uncover serious welfare concerns for the wellbeing of primates kept in American research facilities. These animals face regular or chronic sources of pain and distress including noxious experimental and non‐experimental events and illness and injury; and severe and prolonged social disruptions. Pain relief is meager by comparison to that normally provided to humans, despite legislative requirements to minimize pain and distress and assume similarity to humans in terms of ability to experience pain and distress. Living environments are usually confinement indoors to a metal cage, often alone, and often with a minimum of …


Evolutionary Pressures On Primate Intertemporal Choice, Jeffrey R. Stevens May 2014

Evolutionary Pressures On Primate Intertemporal Choice, Jeffrey R. Stevens

Department of Psychology: Faculty Publications

From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species' environment. Here, I use phylogenetic regression to test whether allometric factors (relating to body size), relative brain size, and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes …


Is There Variation In The Effects Of Primate Size As Seed Dispersers?: Seed And Seedling Performance After Gut Simulation Treatments In Hydrochloric Acid, Denise Chac May 2014

Is There Variation In The Effects Of Primate Size As Seed Dispersers?: Seed And Seedling Performance After Gut Simulation Treatments In Hydrochloric Acid, Denise Chac

Chancellor’s Honors Program Projects

No abstract provided.


Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon Jan 2014

Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon

Dartmouth Scholarship

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that …


Wild Justice Redux: What We Know About Social Justice In Animals And Why It Matters, Jessica Pierce, Marc Bekoff Jun 2012

Wild Justice Redux: What We Know About Social Justice In Animals And Why It Matters, Jessica Pierce, Marc Bekoff

Ethology Collection

Social justice in animals is beginning to attract interest in a broad range of academic disciplines. Justice is an important area of study because it may help explain social dynamics among individuals living in tightly- knit groups, as well as social interactions among individuals who only occasionally meet. In this paper, we provide an overview of what is currently known about social justice in animals and offer an agenda for further research. We provide working definitions of key terms, outline some central research questions, and explore some of the challenges of studying social justice in animals, as well as the …


Tool Use In Fishes, Culum Brown Mar 2012

Tool Use In Fishes, Culum Brown

Sentience Collection

Tool use was once considered the sole domain of humans. Over the last 40 years, however, it has become apparent that tool use may be widespread across the animal kingdom. Pioneering studies in primates have shaped the way we think about tool use in animals, but have also lead to a bias both in terms of our expectations about which animals should be capable of using tools and the working definition of tool use. Here I briefly examine tool use in terrestrial animals and consider the constraints of the current working definition of tool use in fishes. Fishes lack grasping …


Runx2 Tandem Repeats And The Evolution Of Facial Length In Placental Mammals, Jason M. Kamilar, Marie A. Pointer, Vera Warmuth, Stephen G.B. Chester, Frédéric Delsuc, Nicholas I. Mundy, Robert J. Asher, Brenda J. Bradley Jan 2012

Runx2 Tandem Repeats And The Evolution Of Facial Length In Placental Mammals, Jason M. Kamilar, Marie A. Pointer, Vera Warmuth, Stephen G.B. Chester, Frédéric Delsuc, Nicholas I. Mundy, Robert J. Asher, Brenda J. Bradley

Anthropology Department Faculty Publication Series

Background

When simple sequence repeats are integrated into functional genes, they can potentially act as evolutionary ‘tuning knobs’, supplying abundant genetic variation with minimal risk of pleiotropic deleterious effects. The genetic basis of variation in facial shape and length represents a possible example of this phenomenon. Runt-related transcription factor 2 (RUNX2), which is involved in osteoblast differentiation, contains a functionally-important tandem repeat of glutamine and alanine amino acids. The ratio of glutamines to alanines (the QA ratio) in this protein seemingly influences the regulation of bone development. Notably, in domestic breeds of dog, and in carnivorans in general, the ratio …


Chimpanzee (Pan Troglodytes) Responses To Visitors Using Chimpanzee-Friendly Behaviors, Daniella Bismanovsky Jan 2012

Chimpanzee (Pan Troglodytes) Responses To Visitors Using Chimpanzee-Friendly Behaviors, Daniella Bismanovsky

All Master's Theses

Many studies suggest that zoo visitors are a cause of stress among animals; among primates, visitor presence can lead to an increase in aggressive displays, time spent non-visible to the public, and a decrease in overall activity. This study tested the effectiveness of using species-specific behaviors among a group of captive chimpanzees. There were 2 conditions: a control, and an experimental condition in which visitors were asked to adopt a stooped posture or lean on the railing, and show a chimpanzee play face. The visitors stooped their posture, sat, and leaned on the railing significantly more in the experimental condition …


Fracture In Teeth—A Diagnostic For Inferring Bite Force And Tooth Function, Paul J. Constantino, Brian R. Lawn, James J.-W. Lee, Peter W. Lucas Apr 2011

Fracture In Teeth—A Diagnostic For Inferring Bite Force And Tooth Function, Paul J. Constantino, Brian R. Lawn, James J.-W. Lee, Peter W. Lucas

Biological Sciences Faculty Research

Teeth are brittle and highly susceptible to cracking. We propose that observations of such cracking can be used as a diagnostic tool for predicting bite force and inferring tooth function in living and fossil mammals. Laboratory tests on model tooth structures and extracted human teeth in simulated biting identify the principal fracture modes in enamel. Examination of museum specimens reveals the presence of similar fractures in a wide range of vertebrates, suggesting that cracks extended during ingestion or mastication. The use of ‘fracture mechanics’ from materials engineering provides elegant relations for quantifying critical bite forces in terms of characteristic tooth …