The East Alpine region formed an important crossroads in later prehistoric Europe, through which ideas, people and objects flowed. This was particularly the case during the Late Bronze Age/ Early Iron Age, when an increasingly competitive society was evolving, with the formation of more complex social structures and the rise of ‘elites’. This has been evidenced in a shift in burial customs, from Urnfield-type cremation burial to the construction of tumuli and the adoption of elaborate inhumation burial. This multidisciplinary, multi-scalar approach to the analysis of human remains aims to explore the evolving structure, homogeneity and heterogeneity of communities inhabiting central and eastern Slovenia, and north-eastern Croatia, during the Late Bronze Age and Early Iron Age. The application of multiple methods, including the osteological analysis of cremated and non-cremated human remains, radiocarbon dating, stable isotope analysis (carbon, nitrogen, oxygen and strontium) and aDNA analysis has facilitated the exploration and interpretation of later prehistoric social structure and lifestyle. The use of carbon (from enamel carbonate and collagen) and nitrogen stable isotope analysis has highlighted important dietary distinctions between communities inhabiting this region and previous studies from elsewhere in contemporary Europe – specifically a high dependence on millet as a staple crop. This has been evidenced by δ13C values of between -17‰ and -15.3‰ from bone collagen. δ15N values of between 7.6‰ and 9.1‰ support this interpretation as they do not indicate the consumption of marine protein. Increased δ15N values of up to 13.5‰ from deciduous dentine have been interpreted as the influence of dietary and metabolic conditions, particularly in the presentation of an Infant exhibited palaeopathological evidence of severe metabolic disease. Complementary isotopic methods, including oxygen isotope ratios and enamel carbonate carbon, have also highlighted heterogeneity in childhood diet, reflecting the transition from a high lipid diet of breastmilk, to a diet of carbohydrates, indicative of weaning. In addition to these findings, the application of radiocarbon dating on cremated and nio-cremated human bone has expanded the current understanding of mortuary practices in this study area. Inhumation burial, previously thought synomemous with the Iron Age, has been now been identified throughout the Bronze Age at the cemetery of Obrežje. The application of this multi-scalar approach to combining and interpreting these data sets has allowed for the investigation of individual biographies, as well as regional trends. This research illustrates the advantages of bringing together multiple lines of evidence for the creation of informed interpretations regarding the life, death and diet of prehistoric peoples of the East Alpine region, and beyond. / The Encounters and Transformations in Iron Age Europe (ENTRANS) Project, led by Ian Armit, with the Slovenian and Croatian principal investigators, Matija Črešnar and Hrvoje Potrebica. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 291827. The project is financially supported by the HERA Joint Research Programme (www.heranet.info) which is co-funded by AHRC, AKA, BMBF via PT-DLR, DASTI, ETAG, FCT, FNR, FNRS, FWF, FWO, HAZU, IRC, LMT, MHEST, NWO, NCN, RANNÍS, RCN, VR and The European Community FP7 2007-2013, under the Socio-economic Sciences and Humanities programme. / The Appendices A-H are not available online.

Migration is a widespread and complex phenomenon in nature that has fascinated humans for centuries. Connectivity among populations influences their demographics, genetic structure and response to environmental change. Here, I used the loggerhead turtle (Caretta caretta, L.) as a study organism to address questions related to migratory connectivity and carry-over effects using satellite telemetry, stable isotope analysis and GIS interpolation methods. Telemetry identified foraging areas previously overlooked for loggerheads nesting in Florida. Next, I validated and evaluated the efficacy of intrinsic markers as a complementary and low cost tool to assign loggerhead foraging regions in the Northwest Atlantic Ocean (NWA), using both a spatially implicit and spatially explicit (isoscapes) approach. I then focused on the nesting beaches and developed a common currency for isotopic studies based on unhatched eggs, which provide a non-invasive and non-destructive method for more extensive sampling to elucidate isotopic patterns across broader spatiotemporal scales. Lastly, I found that intra-population variations in foraging strategies affect annual and long-term reproductive output of loggerheads nesting in Florida. Understanding geospatial linkages is critical to the fostering of appropriate management and conservation strategies for migratory species. My multi-faceted approach contributes to the growing body of literature exploring migratory connectivity and carry-over effects.

The West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. The present study expands on previous work on manatee feeding ecology by both assessing the application of stable isotope analysis to manatee tissue and providing critical baseline parameters for accurate isotopic data interpretation. The present study was the first to calculate stable isotope turnover rate in the skin of any marine mammal. Stable carbon and nitrogen isotope ratios were examined over a period of more than one year in the epidermis of rescued Florida manatees that were transitioning from a diet of aquatic forage to terrestrial forage (lettuce) in captivity. Mean half-life for 13C turnover in manatee epidermis was 55 days and mean half-life for 15N turnover was 42 days. Due to these slow turnover rates, carbon and nitrogen stable isotope analysis in manatee epidermis is useful in summarizing average dietary intake over a long period of time rather than assessing recent diet. In addition to turnover rate, a diet-tissue discrimination value of 2.8‰ for 13C was calculated for long-term captive manatees on a lettuce diet. Turnover and diet-tissue discrimination results were subsequently used to interpret carbon and nitrogen stable isotope data in epidermis samples collected from free-ranging manatees in Florida, Belize, and Puerto Rico. This study was the first application of stable isotope analysis to Antillean manatees. Regional differences in stable isotope ratios in manatee skin were consistent with ratios in plant samples collected in those regions. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed mainly of seagrasses, whereas those of Florida manatees exhibited greater variation. Mixing model results indicated manatees sampled from Crystal River and Homosassa Springs had an overall average intake of primarily freshwater vegetation whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs fed primarily on seagrasses. Possible diet tissue discrimination values for 15N ranged from 1.0 to 1.5‰. Stable isotope analysis can be successfully applied to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation vs. seagrasses, and can aid in improving conservation efforts.

Thesis advisor: Ethan Baxter / Thesis advisor: Mark Behn / Subduction zones are areas of significant mass transfer between Earth’s crust and mantle. The dehydration of water-rich minerals such as serpentinite and lawsonite introduces water and volatiles into the subduction interface, that then travel to the mantle wedge above. The chemical composition, speciation, and redox effect of these fluids carry important implications for arc volcanism and the mobility of economically significant elements. This study uses Fe and Zn isotopic variation in eclogite-breccias from the Monviso ophiolite, combined with Sm-Nd garnet geochronology, to study the composition and redox effects of fluids that were produced during eclogite and blueschist facies metamorphism, and the timescales over which the brecciation and fluid flux events happened. Fe and Zn isotopic measurements were made on a series of four breccia matrix generations (M1-M4), generated during the progressive brecciation of the original Fe-Ti gabbros and the influx of both internally and externally derived fluids. The ∂56Fe and ∂66Zn data display a bi-modal distribution, with early matrix crystallization (M1-3) imparting progressively lighter ∂66Zn values while the ∂56Fe remains relatively unchanged. The last stage of metasomatic rind formation (M4) is associated with a decrease in both Fe and Zn isotopic values and a particularly significant shift in the Fe isotopes. This distribution suggests that early brecciation (M1-3) resulted from small-scale internal fluid flow that did not have a measurable effect on the isotopic composition and redox state of the system. By contrast, late metasomatic rind formation (M4) was facilitated by the flow of large amounts of external fluids with a strongly negative Fe and Zn isotope signature that affected the redox state of the mafic slab and may be responsible for transferring oxidized material into the mantle wedge. Dating of the M4 matrix generation yielded an age of 41.31± 0.60 Ma. A compilation of age data from Monviso suggests peak metamorphism and initial brecciation (M1 formation) likely occurred at ~45 Ma, the formation of the M4 matrix representing the end of eclogite-facies retrogression and brecciation at ~41 Ma, and final blueschist and greenschist retrogression at ~38-35Ma, yielding timescale of ~4Ma for the entire history of brecciation and fluid flux associated with the Monviso eclogite breccias. / Thesis (MS) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Earth's climate is prone to natural and episodic cycles. The most recent period of climate change, the only one to be caused by humans, is significantly affecting species composition and landscapes. Northern expansion of the Boreal Forest in Canada is one of the expected outcomes, and tree line migration northward is one of the anticipated changes. Previous studies have found that many human activities like agriculture, grazing, and pastoralism can significantly affect tree line movement. Improving our ability to examine past tree line dynamics can be achieved using archival records in lake sediments. In this study, we focused on three sediment biomarkers that may be related to the presence of trees in a lake's catchment: n-alkanes, lignin-derived phenols, and stable isotopes of carbon. We examined the composition of these markers in sediment from 19 lakes in Saskatchewan spanning 4 ecoregions, from Prairie Grassland to Boreal Plain, to determine the biomarker signature for lakes in each ecoregion and relating them to land cover (trees vs herbaceous plants) in the catchments of each lake. The results showed that n-alkane composition was significantly correlated to the proportion of trees to herbaceous plants in a lake's catchment, raising the possibility that these can be used to infer the presence of trees in sediment records. The C/N ratio and δ¹³C were not effective in distinguishing ecoregions or land cover composition, likely due to algal production in the lake and agricultural activities in the surrounding farmland, while lignin-derived phenols appeared to be affected by unknown factors.

Accelerating rates of urbanization create novel compilations of species in urban ecosystems which experience unprecedented proximity to large human populations. Although an integral part of these urban ecosystems, mammals are difficult to study in urbanized areas. However, questions regarding urban mammalian ecology, such as the maintenance or disruption of predator-prey relationships, are vital to understanding what impacts anthropogenic factors may exert on the functions of urban ecosystems. We show that non-trapping hair equipment can effectively collect hair samples from two mammal groups – small mammals and mesopredators – in urban areas for the purpose of addressing ecological questions. We deployed non-trapping hair collection equipment at 16 different parks, preserves, and nature areas along the urbanization gradient of Philadelphia, Pennsylvania. We collected a total of 354 small mammal and 41 mesopredator hair samples. Of these samples, 58 small mammal samples and 14 mesopredator samples were of adequate weight for stable isotope analysis. We analyzed relationships between δ15N and δ13C values from each species and percent impervious surface (our proxy for urbanization) to explore potential shifts in mammal diets. Our results indicated a decoupling of predator-prey relationships between mesopredators and small mammals, particularly in urban spaces and suggested that mesopredators may be relying upon anthropogenic food subsidies. Our methodology was not only effective in addressing an ecological question, but it also provided a unique opportunity to connect with community members through QR code labels attached to our field equipment. Non-trapping hair collection methods offer a viable way to collect useful samples in urban areas while also fostering connections between community members and field research occurring in their neighborhoods. / Biology

When a society experiences a collapse, political authority becomes decentralized, large settlements often become abandoned, economic specialization decreases; and monumental building projects, artistic, and literary achievements slow drastically. The Rio Verde Valley, a coastal floodplain located in the region of Oaxaca in Southwest Mexico, experienced such a collapse at the end of the Terminal Formative period (150 BC to 250 AD). A period of decentralization followed, with regional centers becoming the main seats of authority throughout the region. My aim is to understand how this collapse affected residential population mobility in the lower Rio Verde Valley between the pre-collapse Terminal Formative and post-collapse Early Classic periods. I seek to answer the question: could this political collapse have caused intra-regional migration amongst the people of Ancient Oaxaca? To answer this, I analyzed the stable 18O and 13O isotopes in a set of 21 samples of human long bone excavated from the Terminal Formative archaeological site of Yugüe and the Early Classic site of Charco Redondo. Oxygen isotope analysis is based on the principle that bone apatite and tooth enamel hold traces of oxygen isotopes found in the water that people drink, and that varying values of those isotopes reflect that the water was obtained from different sources. Based on literature surrounding the process of political collapse in ancient Mesoamerica and beyond, I expected to find evidence that intra-regional population mobility increased after the Terminal Formative period collapse. Instead, I found evidence of little to no mobility in both the Terminal Formative period site and the Early Classic period site, showing that the political collapse likely did not affect intra-regional mobility. These findings provide valuable insight into how human migration patterns correspond with political changes, both in the archaeological record of past civilizations and in modern societies.

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