Biological and Physical Anthropology Commons^™

Reimagining The Inner Ear: A Morphometric Modeling Approach For Establishing Shape Change In The Evolution Of The Human Otolith System, Christopher M. Smith

Dissertations, Theses, and Capstone Projects

Our sense of balance is among the most central of our sensory systems, particularly in the evolution of human positional behavior. The peripheral vestibular system of the inner ear comprises the organs responsible for this sense; the semicircular canals (detecting angular acceleration) and otolith organs (utricle and saccule; detecting linear acceleration, vibration, and head tilt relative to gravity). The vestibular organs are often considered a single system, with most research focusing on the semicircular canals. The otolith organs, by comparison, remain largely unexplored despite their central role in balance. Consequently, this lack of knowledge limits understanding of vestibular functional morphology …

Fatty Females And Muscular Males: Investigating Human Sexual Dimorphism Across The Upper And Lower Skeleton, Brooklin Edwards

Anthropology Undergraduate Honors Theses

The sexual dimorphism profile of human body composition produces a unique pattern. Compared to other primates, humans have a mild size dimorphism; however, human males have a particularly muscular upper body and human females have a permanent fatty composition. These findings have resulted in varying interpretations related to sexual selection, mating systems, and male competition. Using humerus and femur measurements collected from 9 primate species, we investigated how the pronounced sexually dimorphic tissue composition of humans influences skeletal elements compared to the other primates. We hypothesized that over the course of human evolution, human females developed a body composition that …

Patterns Of Recent Natural Selection On Genetic Loci Associated With Sexually Differentiated Human Body Size And Shape Phenotypes, Audrey M. Arner, Kathleen E. Grogan, Mark Grabowski, Hugo Reyes-Centeno, George H. Perry

Anthropology Faculty Publications

Levels of sex differences for human body size and shape phenotypes are hypothesized to have adaptively reduced following the agricultural transition as part of an evolutionary response to relatively more equal divisions of labor and new technology adoption. In this study, we tested this hypothesis by studying genetic variants associated with five sexually differentiated human phenotypes: height, body mass, hip circumference, body fat percentage, and waist circumference. We first analyzed genome-wide association (GWAS) results for UK Biobank individuals (~194,000 females and ~167,000 males) to identify a total of 114,199 single nucleotide polymorphisms (SNPs) significantly associated with at least one of …

Climbing Performance And Ecology In Humans, Chimpanzees, And Gorillas, Elaine E. Kozma

Dissertations, Theses, and Capstone Projects

This dissertation aims to establish the effects of limb proportions and body size on the climbing performance of humans, chimpanzees, and gorillas by assessing three aspects of climbing performance: 1) energetic cost, 2) fatigue, and 3) canopy access. Whether hominins were arboreal, and to what extent, is a matter of hot debate. Specifically, the relative prominence of vertical climbing in the locomotor repertoires of various hominin taxa remains a contested issue. Over the course of human evolution, both the body size and relative hindlimb length of hominins has increased. These traits are often linked to bipedality. Long forelimbs, in contrast, …

Convergence Of Human And Old World Monkey Gut Microbiomes Demonstrates The Importance Of Human Ecology Over Phylogeny, Katherine R. Amato, Elizabeth K. Mallott, Daniel Mcdonald, Nathaniel J. Dominy, Tony Goldberg, Joanna E. Lambert, Larissa Swedell, Jessica L. Metcalf, Andres Gomez, Gillian A. O. Britton, Rebecca M. Stumpf, Steven R. Leigh, Rob Knight

Publications and Research

Background

Comparative data from non-human primates provide insight into the processes that shaped the evolution of the human gut microbiome and highlight microbiome traits that differentiate humans from other primates. Here, in an effort to improve our understanding of the human microbiome, we compare gut microbiome composition and functional potential in 14 populations of humans from ten nations and 18 species of wild, non-human primates.

Results

Contrary to expectations from host phylogenetics, we find that human gut microbiome composition and functional potential are more similar to those of cercopithecines, a subfamily of Old World monkey, particularly baboons, than to those …

Evolution Of Endurance Running Genes Across Primates, Natalia T. Grube

Theses and Dissertations

The endurance running hypothesis has emerged as a key idea to explain several unique anatomical, physiological, and genetic features of modern humans—among these features is the evolution of ACTN3 (Bramble & Lieberman 2004, Nature), a gene linked to human athletic performance. An additional gene linked to human endurance performance is ACE. Because endurance running is a uniquely human trait, I predicted that ACE and ACTN3 genes would be evolving adaptively in the human lineage when examined in a wider primatological framework. To test this I compiled ACE and ACTN3 genes from 14 primate species and phylogenetically tested if these genes …

Drawing The Line: Ancient Hominins And The Species Question, Erin Hurley, Carolyn Dillian

Honors Theses

he present paper asserts that groups such as Neandertals and Denisovans should be considered subspecies of H. sapiens. This contention is based upon the biological species concept and the fact that these groups interbred to create viable offspring. It is also stated that introgression from these groups made several positive contributions to the evolution of H. sapiens and their genome that may have served to promote the persistence of H. sapiens in Eurasia.

Utilizing Craniometrics To Examine The Morphological Changes To Homo With The Advent Of Processing Food By Cooking, Julia Schorr

Graduate Student Theses, Dissertations, & Professional Papers

This thesis examines the extent to which the development of cooking by early humans contributed to morphological changes in the human skull, hypothesizing that the cooking of food by early humans had a direct effect on human evolution, leading to smaller face shape, larger body size, and larger brain development, which can be measured in the skull using craniometrics. Beginning with Homo erectus around 1 million years ago, early humans began cooking food. By beginning the process of physical and chemical breakdown of food prior to consumption, humans were able to better access calories and nutrients already found in their …

Evolution Of The Human Diet: What We Can Learn From Hunters And Gatherers, Kara Osborne, Alyssa Crittenden

McNair Poster Presentations

The study of hunter-gatherer populations around the world can greatly inform our understanding of the evolution of the human diet. Ethnographic research of modern hunter-gatherers has been used to infer the possible food consump­tion and acquisition patterns of our ancestors. Hunter-gatherers provide the in­formation necessary for the understanding of the past human diet, due to these populations living similar lifestyles in similar environments, therefore procuring similar foods.

The Hadza, a group of nomadic hunters and gatherers living in Tanzania, East Africa, are one of the primary populations that nutritional anthropologists study to infer what possible foods our ancestors acquired and …

Paranthropus Boisei: Fifty Years Of Evidence And Analysis, Bernard A. Wood, Paul J. Constantino

Biological Sciences Faculty Research

Paranthropus boisei is a hominin taxon with a distinctive cranial and dental morphology. Its hypodigm has been recovered from sites with good stratigraphic and chronological control, and for some morphological regions, such as the mandible and the mandibular dentition, the samples are not only relatively well dated, but they are, by paleontological standards, reasonably-sized. This means that researchers can trace the evolution of metric and nonmetric variables across hundreds of thousands of years. This paper is a detailed1 review of half a century’s worth of fossil evidence and analysis of P. boisei and traces how both its evolutionary history and …

A Multivariate Test Of Evolutionary Stasis In Homo Sapiens, Jon Geoffrey Kleckner

Dissertations and Theses

In the past, efforts to prove or disprove stasis in hominids have relied upon univariate tests such as Students's t-test. Severe methodological and interpretive problems arise from the misapplication of univariate statistics to questions concerning variation in shape through time. These are questions best addressed using the multivariate approach of morphometrics. Eighteen cranial dimensions drawn from 33 mid and late Pleistocene Homo sapiens were examined using principal component analysis (PCA). PCA divided the sample into two distinct morphologies. Archaic Homo sapiens of the mid Pleistocene clustered with Wurm I neanderthals and apart from post Gottweig early anatomically modern Homo sapiens. …