Life Sciences Commons^™

The Impact Of Delay On Retrieval Success In The Parietal Memory Network, Nathan Anderson

Arts & Sciences Electronic Theses and Dissertations

Recent work has identified a Parietal Memory Network (PMN), which exhibits regular patterns of activation during memory encoding and retrieval. Among these characteristic patterns, this network displays a strong “retrieval success” effect, showing greater activation for correctlyremembered studied items (hits) compared to correctly-rejected novel items (CRs). To date, most relevant studies have used short retention intervals. Here, we ask if the retrieval success effect seen in the PMN would remain consistent over a delay. Twenty participants underwent fMRI while encoding and recognizing scenes. Greater activity for hits than for correctly-rejected lures within PMN regions was observed after a short delay …

Neurogenetics Of The Externalizing Spectrum, Caitlin E. Carey

Arts & Sciences Electronic Theses and Dissertations

Externalizing spectrum disorders, which include attention-deficit/hyperactivity disorder, oppositional defiant disorder, conduct disorder, alcohol and substance use disorders, and antisocial personality disorder, are characterized by behavioral disinhibition and are thought to be manifestations of a common heritable liability factor throughout the lifespan. However, relatively little is known about their underlying etiology. Here, I probe genetic and neural risk mechanisms for externalizing psychopathology in three complementary studies. First, I report an indirect association between genetic risk for childhood attention-deficit/hyperactivity disorder (ADHD) and problem drinking in young adulthood, mediated by heightened reward-related neural activity within the ventral striatum, among 404 college students. I …

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 …

Coexistence Of Confamilial, Folivorous Indriids, Propithecus Diadema And Indri Indri, At Betampona Strict Nature Reserve, Madagascar, Lana Kerker Oliver

Arts & Sciences Electronic Theses and Dissertations

In this dissertation, I examine how two confamilial and ecologically similar indriids, indri (Indri indri), and diademed sifakas (Propithecus diadema) maintain coexistence in Betampona Nature Reserve (BNR), an eastern lowland rainforest in Madagascar. These two species occur sympatrically throughout much of their species ranges and are similarly-sized folivorous primates. As anatomic folivores, they present an opportunity to investigate how niche differentiation and resource partitioning allow two sympatric primate species with similar feeding patterns to coexist. I examined coexistence strategies and the general behavioral ecology of each species by examining their activity patterns, dietary profiles, home range use, and daily path …

Process-Based Modelling Shows How Climate And Demography Shape Language Diversity, Michael C. Gavin, Thiago F. Rangel, Claire Bowern, Robert K. Colwell, Kathryn R. Kirby, Carlos A. Botero, Michael Dunn, Robert R. Dunn, Joe Mccarter, Marco Tulio Pacheco Coelho, Russell D. Gray

Biology Faculty Publications & Presentations

Aim

Two fundamental questions about human language demand answers: why are so many languages spoken today and why is their geographical distribution so uneven? Although hypotheses have been proposed for centuries, the processes that determine patterns of linguistic and cultural diversity remain poorly understood. Previous studies, which relied on correlative, curve-fitting approaches, have produced contradictory results. Here we present the first application of process-based simulation modelling, derived from macroecology, to examine the distribution of human groups and their languages.

Location

The Australian continent is used as a case study to demonstrate the power of simulation modelling for identifying processes shaping …