QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation.
Integrating Steller Sea Lion Archaeogenomics with Archaeological Data to Understand Human-Marine Ecosystem Interactions and Demographic Shifts in the Kuril Islands
Abstract: This project uses ancient DNA analysis of Steller sea lion remains from the Kuril Islands to investigate a human population collapse that occurred around 1000 B.P., associated with the Okhotsk culture. I will also provide paleoecological data that can be used to better understand contemporary pinniped populations and the threats facing them. Sea lions are being used to investigate human population collapse because they were relied on both for subsistence and resources by the people of the Kuril Islands. If the decline in the Okhotsk population is related to a decrease in the abundance of marine resources, a correlating bottleneck in sea lion populations may be evident in the archaeogenomic record. A sea lion population bottleneck would not be the direct cause of a human population decrease, but it would signal human pressure on the marine environment and/or an external climatic event affecting people and their resources. If there is no change in population structure of sea lions during the Okhotsk collapse, environmental stresses may not have been a factor in their decline. I will use the genetic data obtained from the sea lions to test for ancient population structure in sea lions, test for demographic decline, and look for signs of “genomic meltdown.” This research serves as pilot work for my dissertation in which I will use these methods as a means for understanding larger scale human-marine environment interactions in the North Pacific Rim region throughout the Holocene.
Ancient plant community and climate of the Pacific Northwest (USA) during the Middle Miocene Climatic Optimum: The Emerald Creek Flora of Northern Idaho
Abstract: This study will combine plant microfossils (i.e., pollen/spores and phytoliths) and macrofossils (e.g., leaves) from the Emerald Creek flora of Idaho to reconstruct vegetation and climate during the Middle Miocene Climatic Optimum (MMCO). The MMCO occurred ~17–14 million years ago and is one of Earth’s most recent transient warming events. Previous studies of vegetational and climatic response to the MMCO in the western U.S. have utilized different paleobotanical sources (macrofossils or phytoliths) that arrive at conflicting inferences. Understanding why these differences exist is problematic because of several potential confounding factors, including age differences, regional-specific factors (e.g., topography), and differences in what ecological information each source captures, particularly within patchy landscapes. I hypothesize that different paleobotanical sources reflect vegetation within distinct areas of the landscape and thus confound comparisons between studies using different sources when ancient vegetation was patchy. By integrating paleobotanical sources from a single fossil site and sediment horizon I will provide a spatially and temporally resolved perspective of vegetation and climate. Specifically, I predict that at Emerald Creek, macrofossils will disclose a diverse, mainly broadleaved riparian forest, while pollen and phytoliths will disclose an upland, open-habitat grassland—woodland mosaic, all existing in a warm-temperate sub-arid climate. This study will demonstrate the utility of using multiple paleobotanical sources in gaining a comprehensive view of ancient vegetation and climate and provide such a perspective for vegetation and climate in the Pacific Northwest during the MMCO.
The utility of palm phytoliths for inferring the evolution and paleoecology of Arecaceae
Abstract: Palms (family Arecaceae) are ecologically important in a range of different tropical and subtropical ecosystems (e.g., rainforest, mangroves, savannas). We propose to study the utility of palm bio-silica bodies (phytoliths) for distinguishing palms from different taxonomic groups and with different ecologies (e.g., climate, habitat preference) in the fossil record. Being able to do so would enhance the ability of paleobotanists and archaeobotanists to (1) reconstruct the evolutionary history of palms, (2) infer ancient habitats and climates from fossil palm phytoliths in paleontological samples, and (3) track the domestication of palm species (e.g., Cocos nucifera, Phoenix dactylifera). Our approach is to measure phytolith shape and size variation in modern palm species from across the palm family using phytolith outlines obtained from confocal microscope images. We will test for phylogenetic signal, identify clade synapomorphies and examine correlations with habitat and climate.
The data produced by this study will be made available to the scientific community through a publication and through the online database of the Burke Museum, and will be of interest to scientists in all major fields of research at QRC.
Using modern phytoliths to determine the spatial resolution of the phytolith fossil record
Abstract: Phytoliths have been traditionally used to address a variety of questions in archaeobotany and Quaternary paleoecology. Nevertheless, in the last 15 years phytolith analysis has became a powerful tool for multidisciplinary studies in deep-time paleoecology and evolutionary biology. As the field of phytolith analysis is in expansion, it is crucial that we refine this tool by establishing more rigorous protocols allowing applications and comparisons among a wide range of studies. In line with the currently increasing body of work on phytoliths in modern plants, soil and habitats, my research focuses on phytoliths as a tool to reconstruct habit structure (heterogeneity) in space, across different Neotropical ecosystems (dry forest, rainforest, and savanna). To reconstruct habitat structure in the fossil record, phytolith workers typically rely on the handful of studies indicating that phytolith assemblages can preserve a local habitat signal. However, a systematic effort to test quantitatively the limits of phytolith analysis for resolving spatial patterns in vegetation is lacking; furthermore, methodological issues of previous studies restrict the application of phytolith analysis to specific time scales (Holocene), regions (North America, and Africa), and habitats (grasslands and savannas). The objective of my research is to partially fill the gap in the knowledge of the spatial resolution of the phytolith record in different Neotropical habitats.
Abstract: This project uses ancient DNA analysis of Steller sea lion remains from the Kuril Islands to investigate a human population collapse that occurred around 1000 B.P., associated with the Okhotsk culture. I will also provide paleoecological data that can be used to better understand contemporary pinniped populations and the threats facing them. Sea lions are being used to investigate human population collapse because they were relied on both for subsistence and resources by the people of the Kuril Islands. If the decline in the Okhotsk population is related to a decrease in the abundance of marine resources, a correlating bottleneck in sea lion populations may be evident in the archaeogenomic record. A sea lion population bottleneck would not be the direct cause of a human population decrease, but it would signal human pressure on the marine environment and/or an external climatic event affecting people and their resources. If there is no change in population structure of sea lions during the Okhotsk collapse, environmental stresses may not have been a factor in their decline. I will use the genetic data obtained from the sea lions to test for ancient population structure in sea lions, test for demographic decline, and look for signs of “genomic meltdown.” This research serves as pilot work for my dissertation in which I will use these methods as a means for understanding larger scale human-marine environment interactions in the North Pacific Rim region throughout the Holocene.