Thure E Cerling

University of Utah | UOU · Department of Geology and Geophysics

Strontium isotope ratios (87Sr/86Sr) of incrementally grown tissues have been widely used to study movement ecology and migration of both extant and extinct animals. However, the timescale of 87Sr/86Sr incorporation from the environment into tissue and how it may influence data interpretation are still poorly understood. Using the relocation of a z...

The Turkana Basin in Kenya/Ethiopia hosts remarkable fossil-rich sediments that are central to our understanding of early hominin evolution, with interbedded volcanic tuffs providing critical time markers. However, the resolution of existing Early Pleistocene/Pliocene ages is limited to ∼20-60 kyr, inhibiting evaluation of climatic/environmental dr...

African forest hogs (genus Hylochoerus) are extant Afro-tropical suids that inhabit a variety of forest environments and thick bushlands and are predominantly herbivores. Hylochoerus likely evolved from a Pleistocene Kolpochoerus majus-like ancestor, but its recent evolutionary history is virtually unknown. Here, we describe a partial right lower t...

Comparative morphometric study of recently recovered fossil elephant molars from Natodomeri, Kenya identifies them as belonging to Elephas jolensis and confirms the presence of this species in Members I and II of the Kibish Formation. Improved datation of these geological units constrains them between 205 and 130 ka. Elephas jolensis is also report...

Significance As Americans, our diets have among the highest protein consumption rates and we are experiencing increased rates of obesity across all age groups. Here we reveal that consumption of corn-fed animal proteins are more common among lower socioeconomic status populations, which places these populations at a potentially greater risk for inc...

Intra-tooth stable isotope variations have been used to interpret seasonality and aridity in paleoenvironmental reconstructions of paleontological and archeological sites. However, most intra-tooth datasets only permit qualitative interpretations of seasonality, because the measured signal is attenuated due to the duration of enamel mineralization...

Stable isotope ratios in tissues of large mammalian herbivores record diet and climate information integrated over large spatial areas and can be used to study modern and fossil ecosystems. Sound interpretation of data requires that tissue growth rates be determined accurately and that ecological and behavioral variables that influence stable isoto...

Diet is a major driver of hominin evolution, but most of the geochemical evidence relies on carbon isotopes (δ 13 C). Here, we report enamel stable calcium isotope (δ 44/42 Ca) values against δ 13 C values for several hominins and co-existing primates in the Turkana Basin area, circa 4 to 2 Ma. Australopithecus anamensis clusters with mammal browse...

Intratooth stable isotope profiles in enamel provide time series of dietary and environmental information that if correctly interpreted, serve as archives of seasonal variability in past environments. A major challenge in interpreting these profiles arises from time averaging imparted by enamel mineralization and developmental geometry, whereby the...

Trace elements in hair originate from intake (e.g., diet, inhalation, skin absorption), are transported in the bloodstream, and then incorporated during hair formation. However, the trace element abundance and isotopic compositions may be altered by post-eruption environmental processes. Such alterations must be addressed to obtain a meaningful int...

In this chapter, the authors lay out basic concepts related to hair and isotope incorporation, as well as known spatial patterns that provide the basis for human provenancing. They consider it is of uttermost importance that researchers considering these analyses understand how hair records the isotopic signals related to diet, drinking water and g...

DeSantis et al. respond to the concerns raised by Van Valkenburgh et al. on their original study

Determining the ages of young volcanic rocks is important for understanding the tectono-magmatic development of geologic terranes. Usually, if rocks are old enough the ⁴⁰Ar/³⁹Ar or K–Ar techniques can provide reliable ages. However, when rocks are younger, they often lack enough daughter product to resolve an age. Cosmogenic ³He methods provide an...

Nursing is pivotal in the social and biological evolution of hominins, but to date, early-life behavior among hominin lineages is a matter of debate. The calcium isotopic compositions (d 44/42 Ca) of tooth enamel can provide dietary information on this period. Here, we measure the d 44/42 Ca values in spatially located microsized regions in tooth e...

The fossils preserved in the Rancho La Brea "tar" seeps in southern California span the past ∼50,000 years and provide a rare opportunity to assess the ecology of predators (e.g., the American lion, sabertooth cats, cougars, dire wolves, gray wolves, and coyotes), including clarifying the causes and consequences of the terminal Pleistocene extincti...

We investigate how oxygen isotopes in equid teeth can be used as a record of seasonality. First, we use in situ laser ablation and conventional microsampling techniques to understand time-averaging of environmental signals in intra-tooth isotope profiles in modern feral horse teeth (n = 5) from Mongolia, where there is a large seasonal gradient in...

As a recorder containing both physiological and environmental information, keratinized tissues, such as hair and feather, can be used to reveal geographical information, to monitor the exposure to pollutants, and to reconstruct dietary history. However, trace element analysis of keratinized tissues is complicated by the lack of reference endogenous...

Whereas mining and non-mining sourced particulate metal/metalloids (PM) (> 0.45 μm) are present in the tributaries of the San Juan River, USA, the individual contributions of PM from the San Juan River tributaries to the sediment of the San Juan River Delta of Lake Powell were previously unknown. Suspended PM signatures, including enrichment factor...

Human activities threaten the biodiversity of aquatic mammals across the globe. Conservation of these species hinges on the ability to delineate movements and foraging behaviors of animals, but gaining such insights is hampered by difficulties in tracing individuals over their lives. We show how isotope ratios in teeth (⁸⁷Sr/⁸⁶Sr, ¹³C/¹²C, and ¹⁸O/...

The spread of early herders across Africa is a pivotal event in prehistory, but the context of this event remains poorly understood due to a lack of paleoenvironmental data. We present new radiocarbon dates and multi-proxy Holocene paleoecological records for two distinct settings on the pathways through which livestock herding spread across easter...

Calcium isotope analyses show a depletion of heavy calcium isotopes in vertebrates, compared to food sources along each trophic step. Recent studies show considerable variability of the calcium isotopic composition of bone and teeth in modern mammals, leading to inconclusive interpretations regarding the utility of Ca isotopes for trophic inference...

The spatial distribution of trace elements in hair is highly heterogeneous at the microscale. The relatively mild spatial variation of endogenous signal incorporated during hair growth may be amplified by orders of magnitude due to later exogenous contaminations. Here, we studied the longitudinal and transverse distributions of trace elements in el...

Stable isotope and elemental ratios in hair are influenced by the environment, including both climate and geology. Stable carbon isotopes can be used to give estimates of the C4/CAM fraction of diets of herbivorous mammals; stable nitrogen isotopes are related to the local water deficit; strontium isotopes are determined by the local geology. We st...

The heart of forensic science is application of the scientific method and analytical approaches to answer questions central to solving a crime: Who, What, When, Where, and How. Forensic practitioners use fundamentals of chemistry and physics to examine evidence and infer its origin. In this regard, ecological researchers have had a significant impa...

Linking human evolution to environmental change is nearly as old as the concept of evolution. As soon as fossils of early humans were identified, questions were posed about how they fit into a story of changing vegetation and climate. Did human evolution occur amidst a backdrop of (or in part because of) expanding grasses and the development of hot...

Carbon isotope ratios of mammalian teeth from the Kanapoi site in northern Kenya are interpreted in the context of C3 and C4 derived resources to investigate the paleoecology of Australopithecus anamensis. δ(13)C values of large mammals, when compared at the taxon level, show an ecosystem that is strongly biased towards mixed feeders and browsers....

Significance Oxygen isotopes in modern and fossil mammals can provide information on climate. In this study, we provide a new record of aridity experienced by early hominins in Africa. We show that past climates were similar to the climate in eastern Africa today, and that early hominins experienced highly variable climates over time. Unexpectedly,...

Organizational structure for the proposed IsoBank. A central executive group would oversee four subcommittees (SC): Information technology, integrative disciplinary, education and training, and analytical expertise. GNIP, Global Network of Isotopes in Precipitation; IAEA, International Atomic Energy Association; QA/QC, quality assurance/quality con...

Rationale: Oxygen isotope ratios (δ(18) O values) of hair largely reflect features of regional hydrology while strontium isotope ratios ((87) Sr/(86) Sr) are thought to reflect bedrock geology; combination of both isotope signatures may provide greater capacity for determining provenance and reconstructing travel history of an organism. To test th...

Significance C-14 dating methods can be used to determine the time of death of wildlife products. We evaluate poaching patterns of elephants in Africa by using ¹⁴ C to determine lag time between elephant death and recovery of ivory by law enforcement officials. Most ivory in recent seizures has lag times of less than 3 y. Lag times for ivory origin...

Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, howeve...

Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements....

The spread of C4 grasses in the late Neogene is one of the most important ecological transitions of the Cenozoic, but the primary driver of this global expansion is widely debated. We use the stable carbon isotopic composition (δ(13)C) of bison and mammoth tissues as a proxy for the relative abundance of C3 and C4 vegetation in their grazing habita...

On August 5, 2015 an accidental blowout from the Gold King Mine, Colorado resulted in the release of trace elements into the San Juan River watershed. The resulting “yellow” river was caused by oxidized metal laden particles. These particles were deposited along the river as the plume moved downstream. Little is known about the mobilization of thes...

Laser ablation of tooth enamel was used to analyze stable carbon isotope compositions of teeth of hominins, red deer, and bears from middle Pleistocene sites in the Sierra de Atapuerca in northern Spain, to investigate the possibility that this technique could be used as an additional tool to identify periods of physiological change that are not de...

Additional information and data related to the laser ablation analysis of hominins from the Sima de los Huesos, Spain. Additional background information is provided regarding tooth enamel formation and diagenesis. Also provided are data comparing average laser ablation stable isotope values to bulk sampling (Table A) as well as all original stable...

Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermophysiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of...

Stable isotope analysis is a promising tool for investigating primate ecology although nuanced ecological applications remain challenging, in part due to the complex nature of isotopic variability in plant-animal systems. The aim of this study is to investigate sources of carbon and nitrogen isotopic variation at the base of primate food webs that...

Stable carbon, nitrogen, hydrogen, and oxygen isotopes have been used to infer aspects of species ecology and environment in both modern ecosystems and the fossil record. Compared to large mammals, stable isotopic studies of small-mammal ecology are limited; however, high species and ecological diversity within small mammals presents several advant...

Objective: Archaeological remains strongly suggest that the Holocene Japanese hunter-gatherers, the Jomon people, utilized terrestrial plants as their primary food source. However, carbon and nitrogen isotope analysis of bone collagen indicates that they primarily exploited marine resources. We hypothesize that this inconsistency stems from the ro...

Significance Stable carbon isotopes give diet information for both modern and fossil mammals and can be used to classify diets as C 4 grazers, C 3 –C 4 mixed, or C 3 browsers. We show that diets of some major African herbivore lineages have significantly changed over the past 4 million years by comparing fossils from the Turkana Basin in Kenya with...

RATIONALE: Hair keratin is a very important material in ecological and archaeological studies because it grows continuously, can be obtained non-invasively, does not require extensive processing prior to analysis and can be found in archaeological sites. Only a few studies have examined seasonal variations in hair isotope values, and there is no pu...

Highly migratory organisms present major challenges to conservation efforts. This is especially true for exploited anadromous fish species, which exhibit long-range dispersals from natal sites, complex population structures, and extensive mixing of distinct populations during exploitation. By tracing the migratory histories of individual Chinook sa...

Dietary analyses of herbivorous mammals are important for paleoecological reconstruction. Several methods applicable to fossil teeth have been developed lately. The mesowear method based on wear-induced occlusal shape and relief of ungulate molars has proven to be a robust method for dietary analysis. In its original form it can only be used for se...

Significance Herding was the earliest form of African food production and transformed local populations of people and animals. Herders migrated from eastern to southern Africa around 2,000 years ago, but only in small numbers. Zoonotic disease vectors, specifically the tsetse fly, which carries sleeping sickness, are thought to have impeded these m...

Heterogeneity in 87Sr/86Sr ratios of river-dissolved strontium (Sr) across geologically diverse environments provides a useful tool for investigating provenance, connectivity and movement patterns of various organisms and materials. Evaluation of site-specific 87Sr/86Sr temporal variability throughout study regions is a prerequisite for provenance...

We report new 87Sr/86Sr ratios of 61 rivers across Alaska's diverse geologic regions.•Regional patterns in carbonate and silicate weathering influence observed multi spatial scale 87Sr/86Sr heterogeneity.•Rivers north of the Denali Fault exhibit higher and more variable 87Sr/86Sr ratios than rivers south of the fault.•North of the Denali Fault, eas...

Dust cycling from the Great Basin to the Rocky Mountains is an important component of ecological and hydrological processes. We investigated the use of strontium (Sr) concentrations and isotope ratios (87Sr/86Sr) in tree rings as a proxy for dust deposition. We report Sr concentrations and isotope ratios (87Sr/86Sr) from atmospherically deposited d...

Objectives We conducted stable isotope and dietary analyses of women from higher and lower socioeconomic status (SES) groups in Cali, Colombia. The objectives were to test between-group differences in stable isotope, dietary, and anthropometric characteristics, and to evaluate relationships between diet and stable isotope values.Methods Hair sample...

We investigated a novel application of stable isotope abundance analysis of nitrogen (15N), carbon (13C), hydrogen (2H), and oxygen (18O) to characterize pen ink. We focused on both ballpoint and gel pen inks. We found that the isotope ratios of ink from pens purchased together in a package were similar and within-package stable isotope ratio varia...

Methods and systems for determining travel history can be based on noninvasive analysis of stable isotope ratios in the body of an individual. A method for reconstructing a travel history for an individual can include collecting a sample of exhaled breath from the individual and analyzing the sample to obtain a breath isotope ratio. The breath isot...