Research

The Ungar Lab is involved in many projects at a given time. To learn about dental microwear and dental topography methods check out their pages or explore our different research pages to learn more about our current research.

Paleoanthropology

Canine Use in Hominins

Team Members: Lucas Delezene, Peter S. Ungar, J. Michael Plavcan, Mark Teaford

Funding Source: Leakey Foundation

Using dental microtexture analysis, we are examining the hypothesis that early hominins used their canines in ingestive behaviors. To do so, we will compare microwear in five hominin species to that of a range of anthropoid primates that use their canines in a variety of preparatory and nonmasticatory contexts.

Rising Star Collaboration: Diet and Tooth Morphology

Team Members: Lucas Delezene, Sarah V. Livengood, Alia Gurtov, Lee R. Berger, and Peter S. Ungar

Funding Source National Geographic; University of the Witwatersrand, Johannesburg

We are examining the microwear textures on the occlusal and buccal surfaces of the Homo naledi material to understand dietary behaviors. Their microwear signals will be compared to modern hunter-gatherers, currently published hominin material, and non human primates.

Kanapoi Paleoecology

Team Members:
Michael Plavcan, Lucas Delezene, Jessica Scott, Elicia Abella, Jenny Burgman, Rachel Walton, and Peter S. Ungar

Funding Source National Science Foundation

The Ungar lab is participating in the paleoecological reconstruction of the hominin site of Kanapoi in Kenya. By analyzing the dental textural analysis of rodents, suids, primates and hominins from the site to understand the dietary patterns of these animals.

Dental Microwear: Comparative Methods

Dental Microwear of the Hadza: Implications for the evolution of human diet

Team Members: Sarah V. Livengood, Alyssa Crittenden (University of Nevada- Las Vegas), Peter S. Ungar

Funding Sources: Leakey Foundation, University of Nevada- Las Vegas, Arkansas Graduate Fellowship in Anthropology, Sigma Xi

Studies of early hominin bones and teeth have led to insights about the diets of our ancestors. Recent dental microwear texture analyses have been especially effective at distinguishing between hominins in ways that separate living primates with differing diets. Analogy with living human foragers and nonhuman primates has also contributed to inferences of early hominin diets by providing important models. Observations that hunter-gatherers living in savanna settings rely on meat and underground storage organs (USOs) have led to the idea that one or the other might be a critical keystone resource associated with the emergence of the genus Homo.

There has been a disconnect between researchers studying hominin teeth and those who model diet among modern hunter-gatherers. To date, no research has tested whether meat or USO consumption by human foragers leaves identifiable differences in dental microwear or whether the resulting patterns can be matched with actual microwear on early hominin teeth. This dental microwear analysis of a living hunter- gatherer group, the Hadza of Northern Tanzania, will augment our comparative database of microwear textures with a living traditional foraging group, and document unprecedented detail relating diet to pattern, and it will use seasonal variation in Hadza diet to test the hypothesis that hunter-gatherer diets dominated by USOs and vertebrate meat result in significantly different microwear patterns. By comparing the resulting patterns with those already collected and published for early hominins, particularly early Homo, we can determine whether these patterns increase our understanding of the roles that meat and USOs played in evolution of human diet. This study further develops tools to provide insights into the effects of diet on the evolution of our ancestors.

SSFA Development and Instrumentation Comparisons

Team Members: Peter S. Ungar, Sam Arman, Chris Brown, Anna Ragni

We are continuing to develop new protocols for dental microwear texture analysis, and updating instrumentation to take advantage of new technologies.

Australian Marsupial Research

Team Members: Sam Arman, Gavin Prideaux, Grant Gully

Funding Sources: Australian Research Council, Flinders University

Our laboratory is collaborating with Gavin Prideaux (Flinders University) and his staff and students to use microwear to help better understand the evolution of marsupial herbivores in Australia, including macropodine (long faced) kangaroos, sthenurine (short-faced extinct) kangaroos, Diprotodontids (quadrupedal marsupials including the largest marsupials ever), and others. This will also include consideration of the evolution of Australian plants, and the role that Australian biogeography has played in shaping herbivore evolution. This project incorporates dental microwear, mesowear, tooth morphology, stable isotope analysis and enamel thickness methodologies.

IMG_8366

Non-human Primate (Brazil Project)

Team Members: Lucas Delezene, Mark Teaford, Almudena Estalrrich Albo, Carrie Healy, Alexa Wimberly, Claire Hartgrove, Peter S. Ungar

Funding Source:

The Brazil project has multiple lines of research investigating diet of New World Monkeys through dental microwear textural analysis and dental topographic analysis.

One such avenue looks at the relationship between dental microwear and dental topography in Sapajus apella. This project is analyzing the variables of dental microwear texture analysis and the variables of dental topographic analysis for Sapajus apella. While numerous studies have determined the relationship between dental microwear texture analysis and diet, as well as between dental topographic analysis and diet, few have compared these two analyses. This study seeks to identify if there are correlations between these two analyses, and how these correlations may affect the outcome.

The Rodent Project

Team Members: Salvatore Caporale, Charles Withnel, Jenny Burgman, Mikiko Joiner, Peter Ungar

Funding Source: National Science Foundation

Our laboratory is studying rodents as paleoenvironmental proxies. Rodents and other micromammals are ubiquitous at many fossils sites. Because they tend to live in specific habitats and eat foods available to them in those habitats, we can infer aspects of the environments they inhabit if we can learn something about their diets.

This project has several elements, including the study of the teeth of extant rodents from roosts found in different microhabitats within the Cradle of Humankind in South Africa, and those of fossil rodents from early hominin sites such as Swartkrans, Sterkfontein, and Gladysvale. Association of microwear (and isotope) patterns with diet (and habitat) in living rodents is key to using these lines of evidence to help infer diet (and habitat) from fossil teeth. And since fossil rodents are found in the same deposits as early hominins, micromammal microwear can serve as a useful proxy for the environments in which our ancestors lived.
Our incisor microwear project is using the confocal profiler to collect microwear texture data on front teeth with a 100x objective. But rodent molars are too small and the enamel is too thin to use this instrument to study microwear on cheek teeth. Jenny Burgman and Mikiko Joiner are developing a new protocol for 3D measurement of very tiny microwear surfaces using our newest confocal profiler and 150x objective.

Shrew Teeth

Dental Microwear: Applications of Engineering Principles

Dental Biotribology and Nanowear Formation<

Team Members: Peter S. Ungar, Li-cheng Hua, Zhong-rong Zhou, Jin Zheng, Lin-mao Qian

Funding Source: The National Academy of Science of China

We are using principles from engineering to study the tribological properties of teeth.

Dental Microwear Formation Study

Team Members: Peter S. Ungar, David J. Daegling, Li-cheng Hua

Funding Source: The Southeastern Athletic Conference

We are combining dental microwear texture analysis with in vitro study of food fracture by teeth using universal testing machine technology.

Dental Biomechanics and Functional Morphology

New World Monkey Dental Topography

Team Members: Carrie Healy, Aleksis Karme, Mikeal Fortilius, Peter Ungar

A comprehensive analysis of the dental topography of maxillary M2s of New World monkeys using ArcGIS to determine the correlation between diet (both primary and secondary or fall-back) and occlusal topography.

Oral Health

Hadza Oral Health Research

Team Members: Peter S. Ungar, Alyssa Crittenden, John Sorrentino, Jerry Rose

Funding Source: US National Science Foundation

We are examining oral health in the Hadza peoples of Tanzania. Our research is focusing on changes in caries rate, periodontal disease, orthodontic disorders and developmental defects associated with the transition from hunting and gathering to an agriculture-based economy.

Surface Micro-Morphology Characterization of Non-Carious Lesions (NCCLs)

Team Members: Anderson Hara, Sarah V. Livengood, Frank Lippert, Peter S. Ungar

Non-carious cervical lesions (NCCLs) are clinically characterized by tooth substance loss in the region close to the gingival margin or, more specifically, at the cemento-enamel junction. Their development may involve dental erosion, toothbrushing abrasion and/or deflection forces. NCCLs are responsible for affecting the form, function and aesthetic of the teeth and can, often times, be associated with tooth sensitivity.
The long-term goal of this project is to study the development of NCCLs under well controlled conditions, quantifying the tooth loss rate and characterizing the surface micro-morphology of the NCCLs resulting from different dental wear processes individually or in association.

Surface Analysis of Brushed Enamel Surfaces

Team Members: Sarah V. Livengood, Anderson Hara, Frank Lippert, Peter S. Ungar

This project investigates the ability of SSFA and ISO parameters to determine/predict the enamel/dentin abrasivity of toothpastes as an alternative to the current radiotracer method.

Currently all of our research pages are being updated.