Tag: Frances White

Asymmetry of the Dental Arcade in Six Populations from the Indian Sub-Continent 

Presenter(s): Aimee Herubin − Anthropology

Faculty Mentor(s): Jeanne McLaughlin, Frances White

Poster 76

Research Area: Physical science

Deviations from symmetry that arise during development are defined as fluctuating asymmetry (FA). Greater asymmetry is often related to differences in genetic and environmental factors experienced during development with males showing more asymmetry than females. We measured FA in human dental arcades from different Indian social castes. We hypothesized that men and women would have differing degrees of asymmetry as well as individuals in different castes. We measured samples from the John R. Lukacs Dental Cast Collection at the University of Oregon. Our sample consisted of 177 paired mandibles and maxillae (57 females, 120 males). Individuals were from one of six social castes. Permanent dentition was measured in a three-dimensional plane at the cervix between the first incisors and on the distal surface of premolars and molars. 13 landmarks were digitized using a microscribe-3DX© following the protocol of Frost et al (2003). Dental FA was measured by calculating the Procrustes’ distance between each individual and its mirror image. We compared mean asymmetry by sex and caste using a two-way ANOVA. We found significant differences in both the maxilla and mandible FA between castes (F=51.28, DF=5, p<0.0001 and F=19.40, DF=5, p<0.0001, respectively) but not between sexes with no significant interaction term. Our hypothesis that there would be a difference in asymmetry between sexes was not supported, however, our hypothesis that there would be differences in levels of asymmetry between castes was supported. This suggests that there may be genetic or environmental factors influencing dental arcade development differently in different castes.

Comparing Post-Mortem nd Osteological Measures Of Primate 2D:4D Digit Ratios for Sex Determination

Presenter(s): Libardo Gomez − Biology

Faculty Mentor(s): Frances White

Poster 40

Research Area: Natural/Physical Science

The length ratio of the second digit (2D) to the fourth digit (4D) changes with an individual’s exposure to certain hormones prenatally, specifically testosterone (Manning 2002). Scientists therefore use 2D:4D as a proxy for an individual’s testosterone exposure in the uterus; a lower ratio demonstrates higher levels of prenatal testosterone exposure, and a higher ratio demonstrates lower levels of prenatal testosterone exposure (Manning 2002). In primates, testosterone plays a significant role in male-male competition and is therefore higher in males than in females. To collect the most accurate 2D:4D measurements, hands need to be in a fully fleshed stated; due to the limited access to fully fleshed hands, my colleagues and I developed a method to assess accurate 2D:4D ratios post mortem was developed, with results showing articulated bone measurements to have the closest 2D:4D ratio to fleshy skin measurements. Drawing on the many studies that have shown that finger length ratios might be characteristic that can be related to sexual dimorphism (Gillam 2018). We hypothesize that the 2D:4D ratio will be higher in male than female rhesus macaque (Macaca mulatta) and could be used to estimate male from female skeletons. Because rhesus macaques are one of the main non-human primates studied for biological research, this study hopes to expand the body of literature on 2D:4D ratios and prenatal environment effects on bone. Preliminary results show higher male ratios (2D 0.93, 4D 1.14) than in female (2D 0.80,4D 1.02) promising support of this hypothesis.

Abundance, Density, and Diet of Duikers at Lomako, DRC

Presenter(s): Troi Feinberg − General Science

Faculty Mentor(s): Frances White, Colin Brand

Poster 65

Research Area: Natural Science

Duikers are a widespread family of tiny forest-living antelope that occur across sub-Saharan Africa. While approximately 22 species have been identified, little is known about the biology and behavior of many of these species due to their solitary and reclusive nature. Additionally, these species are sensitive to human disturbance and are often among the first species to be hunted and relocate. The objective of this study was to characterize the abundance and density of duikers inhabiting the forest near the N’dele field site in the Lomako Forest Reserve, Democratic Republic of Congo. Auditory or visual observation of duikers was recorded using all-occurrence sampling over nine months from 1983-1984. We also analyzed stomach contents of animals taken by hunters from outside the study area to gain insight on their diets. We encountered three species of duiker at the field site: Cephalophus weynsi, Cephalophus silvicultor, and Philantomba monticola. We detected C. weynsi 63 times, C. silvicultor once, and P. monticola 35 times. A preliminary estimate of overall density was 4.075 per sq. km. across all species. This result is comparable to duiker densities in other protected areas. Analyses of stomach contents (N=6) revealed that C. weynsi consumed at least 23 different plant species, including the following most prevalent food items: Celtis tessmanii, Dialium sp., and Landolphia congolensis. These data contribute to our broader understanding of duiker biology and are useful for monitoring trends in population size and density at this location over time.

What’s in the Box: Using a Comparative Collection to Identify Mystery Avian Bones

Presenter(s): Amelia Delgado − Biological Anthropology

Faculty Mentor(s): Frances White, Madonna Moss

Poster 128

Research Area: Social Science

The UO Primate Osteology Lab had an unmarked collection of bird bones in need of identification. The bones, which were associated with an Excel database, were found to be a project begun by a past graduate student, Brendon Culleton. Many of the bones were labeled with a number and where they were found, however a majority lacked identifications to genus. All bones were collected between 1997 and 1999 from California State Parks such as: Waddell Creek Beach, Golden Gate National Recreation Area, Natural Bridges State Beach, Nisene Marks State Forest, Moss Landing State Beach, Point Lobos Reserve, and Zmudowski State Beach.

For this collection, I worked with Madonna Moss in the Zooarchaeology Lab to learn basic bird anatomy and how to identify the bones with the use of the lab’s avian comparative collection. Learning these skills allowed me to gain experience in curating a researchable collection. This collection was found to include humeri, femora, carpometacarpi and other specialized bird bones, which I identified to genus and organized into an Excel database for future use. Identifications revealed that there were at least 12 species of coastal birds such as scoters, gulls, and western grebes present in the box. Upon completion of this project, this avian bone collection can be utilized for potential teaching aspects of fundamental anatomy of coastal birds.

Dominance Hierarchies Are Not Linear in Semi-Free Ranging Black and White Ruffed Lemurs (Varecia variegata)

Presenter(s): India Brock − Biological Anthropology, Environmental Science

Co Presenter(s): Nora Sawyer

Faculty Mentor(s): Frances White, Colin Brand

Poster 6

Research Area: Primate Behavioral Ecology

Dominance rank and the linearity of social hierarchies have important consequences for social behavior in many species, including many primates. Of particular interest are lemurs, which are the only taxonomic primate group that exhibits female feeding priority and social dominance in multiple genera, including Varecia. Previous research has revealed significantly linear dominance hierarchies in some female dominant species (Lemur catta) but not others (Propithecus verreauxi). Here, we investigate the dominance linearity of another female dominant lemur species: the black and white ruffed lemur. We predicted the dominance hierarchy to be significantly linear both before and after rank changes. We collected behavioral data on semi- free ranging ruffed lemurs (N=8) housed at the Duke Primate Center. We used all-occurrence sampling to record interactions between individuals between Sep 1991 and Mar 1993. We constructed dominance matrices using decided interactions and split the data into one of three time periods based on the eviction of a dominant female. We calculated the dominance linearity (h’) for each time period. Contrary to our prediction, we found no significance difference in linearity across any of the time periods: Pre-Event (h’=0.37, ns), Event (h’=0.33, ns) Post-Event (h’= 0.33, ns). This study demonstrates that ruffed lemurs exhibit a more shallow hierarchy more similar to P. verreauxi than to L. catta.

Assessing The Role Of Crossing Structures In Primate Conservation

Presenter(s): India Brock − Biological Anthropology, Environmental Science

Faculty Mentor(s): Frances White, Larry Ulibarri

Oral Session 4S

Research Area: Primate Conservation

Funding: CAS Continuing Student Scholarship

Anthropogenic modification of natural landscapes is an increasing problem for wildlife, including primates. Infrastructure, including roads, have direct and indirect impacts on wildlife and landscapes. Specifically, mortality from collisions with vehicles and dissection of habitats may reduce population sizes, reduce genetic diversity, and increase genetic differentiation. Road ecology is concerned with understanding and mitigating the effects of roads on wildlife. While this research has focused on a number of taxa, research on primates is particularly scarce. Here, we review the literature for studies on crossing structures as a conservation strategy in wild primate populations. We identified 10 publications on this subject that focused on lemurs (N=1), New World monkeys (N=5), Old World monkeys (N=3), and apes (N=1). We also include data on two unpublished studies. Four bridge designs were used in these studies that varied in their dimensions, construction material, and usage across taxonomic categories. We highlight differences in monitoring and usage across each of these studies. This review highlights a paucity of literature on this oft recommended conservation strategy and an inability to collectively build on previous work from lack of publication. We contend that long-term monitoring of crossing structures be integral to studies on crossing structure. A conceptual framework is proposed for the standardization of crossing structure studies include components for designing purpose-built crossing structures, and avenues for appropriately evaluating bridge effectiveness. We urge the scientific and primatologic communities that primate crossing structure use and effectiveness must be scientifically based.

Swiping for Sex: The Use of Dating Apps and Their Effect on the Evolutionary Costs and Benefits of Human Mating Strategies

Presenter(s): Mariah Bloom – Biological Anthropology

Faculty Mentor(s): Lawrence Sugiyama, Frances White

Poster 127

Research Area: Social Science

Human reproduction is costly, involving both mating (e.g., finding, acquiring, and guarding a mate) and parental effort. The minimal parental investment necessary for women includes egg production, gestation and lactation. Even after weaning, human children require support over an an extended period of juvenile dependence. In ancestral contexts this could not be provided by the mother (or any individual) alone. Women are thus expected to have adaptations motivating them to seek mates who are likely willing and able to invest in her offspring, as well as to seek high genetic quality mates. Women thus deploy complex mating strategies to optimize these qualities, including a strategic mix of both long and short-term mating. The emergence of dating apps may affect the costs of women’s mating effort by allowing them to pre-screen potential mates, with cheaper and easier access to, communication with, and selection among potential long and short-term mates. Sex bias in the number of men and women users may also affect women’s mating strategies. Interestingly, there is limited evolutionarily informed research on how these dating apps have affected women’s mating behavior. This research reviews the literature on women’s use of dating apps & websites through an evolutionary lens: who uses them and why, changing views toward their use, the main mating costs and benefits of their use, and how their use might change women’s sexual behavior over time. Review of this literature will form the basis for generating hypotheses to be tested in the authors senior honors thesis next year.

Niche Separation Between Three Sympatric Lemur Species at Berenty Reserve, Madagascar

Presenter(s): Erick Wonderly

Faculty Mentor(s): Frances White & Colin Brand

Poster 50

Session: Sciences

One of the central goals of ecology is to understand niche differentiation: how different species use the same environment in different enough ways so as to coexist. Typically, this is tested by examining dietary overlap between species. The Lemuriformes, lemurs and their relatives, provide an interesting test of niche differentiation given the antiquity of this superfamily and subsequent adaptation to various unoccupied niches. In this study we first tested for dietary overlap in feeding ecology among three lemur species: Ring-tailed lemur (Lemur catta), Verreaux’s sifaka (Propithecus verreauxi), and Brown lemurs (Eulemur fulvus rufus), at Berenty Nature Reserve, Madagascar. We also considered the degree to which species can monopolize a food source from other species. We analyzed 1,988.16 hours of feeding and social behavior data collected by Alison Jolly between 1988-89 and 1992-93. We found consistent, substantial overlap in the diets of all three lemur species across all four study periods. The majority of aggressive intergroup encounters were within species. Between species encounters rarely resulted in aggression and exclusion from a feeding patch. Collectively, these results suggest greater dietary overlap than previously considered in these taxa and that niche separation beyond lemurs occurs beyond feeding contexts.

Sociosexual behaviors of captive bonobos (Pan paniscus) in proximity to an artificially built termite mound

Presenter(s): Mathieu Wilson

Faculty Mentor(s): Frances White & Kylen Gartland

Poster 109

Session: Social Sciences & Humanities

Studies of wild apes are fundamental to our understanding of humans and human evolution. Biological anthropologists investigate the behavior of our closest relatives, chimpanzees and bonobos, in an effort to understand the evolution of human social behavior. Whereas chimpanzees are male-bonded and aggressive, bonobos have been found to be female-bonded and peaceful. Bonobos are known to engage in sociosexual behaviors for a variety of purposes beyond reproduction. These behaviors are thought to be used to strengthen social bonds and as a means of diffusing group tension in both wild and captive populations. Given these hypotheses, sociosexual behavior is particularly evident in feeding contexts. Here we study the effects of an artificially built termite mounded, baited daily with food, on the sociosexual behaviors of a captive group of 16 bonobos at the Columbus Zoo and Aquarium. To collect data, the bonobos were observed during the day time from June 19th through August 29th, 2011. All occurrences of sociosexual behavior were recorded, in addition to the age and sex of the individuals involved, and who initiated the contact. We hypothesized that (1) the termite mound would bring the group into closer contact in the space near the mound, and (2) that tensions over who had access to the food in the mound would lead to sociosexual behaviors. Our data support that sociosexual behavior is important in both group cohesion and resolving tension in these bonobos.

Reliability and accuracy of post-mortem methods of manual 2D:4D assessment in primates Kendall Soriano, Sarah Brown, Enrique Gomez, Colin M. Brand, Frances J. White

Presenter(s): Kendall Soriano

Co Presenter(s): Sarah Brown

Faculty Mentor(s): Frances White & Colin Brand

Poster 31

Session: Sciences

The ratio of the length of the second to the fourth digitis[AH1] related to levels of prenatal hormone in exposure, specifically testosterone. A lower 2D:4D ratio indicates higher levels of prenatal androgen exposure, and a higher ratio indicates lower levels. Digit length is typically measured from the proximal crease to the most distal end of the digit in living and post-mortem individuals. However, post-mortem processes such as desiccation or decomposition can affect both landmark identification and accuracy of the measure. Digit length can also be measured on osteological specimens, but there is little information on how these measures compare to post- mortem measures. This study compares post-mortem measurements with osteological measurements taken on the same specimens. Here, we compared these measures across multiple primate species (N=40. We also examined the 2D:4D ratio in a macaque foot. First, using a caliper, measurements of the 3 segments in each digit were taken of a fully fleshed foot. Then, after removal of skin and flesh, measurements were taken of bones and tendons. Lastly, measurements of only bones were recorded after removal of tendons. This technique was shown to be an effective way of analyzing digit measurements as the results indicate clear differences in the ratio of digit sizes. This study demonstrates that the disarticulated measurement is the most accurate osteological method of estimating post-mortem 2D:4D. We want to take our knowledge of the relation between 2D:4D ratio and prenatal hormone exposure and apply it to across various other primate species.