Angela L. Lamb

The oxygen isotope relationship between the phosphate and structural carbonate fractions of human bioapatite

RATIONALE Oxygen isotope analysis of archaeological human dental enamel is widely used as a proxy for the drinking water composition (δ(18)O(DW)) of the individual and thus can be used as an indicator of their childhood place of origin. In this paper we demonstrate the robustness of structural carbonate oxygen isotope values (δ(18)O(C)) in bioapatite to preserve the life signal of human tooth enamel by comparing it with phosphate oxygen isotope values (δ(18)O(P)) derived from the same archaeological human tooth enamel samples. METHODS δ(18)O(C) analysis was undertaken on 51 archaeological tooth enamel samples previously analysed for δ(18)O(P) values and strontium isotopes. δ(18)O(C) values were determined on a GV IsoPrime dual inlet mass spectrometer, following a series of methodological tests to assess: (1) The reaction time needed to ensure complete release of CO(2) from structural carbonate in the enamel; (2) The effect of an early pre-treatment with dilute acetic acid to remove diagenetic carbonate; (3) Analytical error; (4) Intra-tooth variation; and (5) Diagenetic alteration. RESULTS This study establishes a direct relationship between δ(18)O(C) and δ(18)O(P) values from human tooth enamel (δ(18)O(P) =  1.0322 × δ(18)O(C) - 9.6849). We have combined this equation with the drinking water equation of Daux et al. (J. Hum. Evol. 2008, 55, 1138) to allow direct calculation of δ(18)O(DW) values from human bioapatite δ(18)O(C) (δ(18)O(DW)  =  1.590 × δ(18)O(C) - 48.634). CONCLUSIONS This is the first comprehensive study of the relationship between the ionic forms of oxygen (phosphate oxygen and structural carbonate) in archaeological human dental enamel. The new equation will allow direct comparison of data produced by the different methods and allow drinking water values to be calculated from structural carbonate data with confidence.

A 9000-year oxygen and carbon isotope record of hydrological change in a small Ethiopian crater lake

The stable isotope composition of authigenic calcites in a core from Lake Tilo, a small crater lake in the Ethiopian Rift Valley, provides a subcentury scale record of lake response to climatic change over the last 8850 14C yrs (9850 cal. yrs). An unusually high range of δ18O and δ13C values (~15,) is attributed, in part, to major changes in hydrothermal groundwater flux. Although hydrothermal groundwater influx to the lake was high during the early Holocene, its flow rate was relatively stable and thus climatically induced changes to the water budget can be inferred from variations in δ18O and δ13C ratios. A major decline in hydrothermal groundwater input from ~5500 14C yrs BP increased lakewater residence time and led to substantial increases in δ18O and δ13C, before the mid-Holocene transition to more arid conditions. During the last ~2700 14C years diagenetic processes have resulted in extremely varied δ18O and δ13C values. The Holocene isotope record from Lake Tilo challenges the widely held assumption that crater lakes act as ’gigantic rain gauges’, sensitive only to changes in precipitation/evaporation ratios.

Modern macaque dietary heterogeneity assessed using stable isotope analysis of hair and bone.

Dietary variability might have been a major factor in the dispersal and subsequent persistence of the genus Macaca in both tropical and temperate areas. Macaques are found from northern Africa to Japan, yet there have been few systematic attempts to compare diets between different modern populations. Here we have taken a direct approach and sampled museum-curated tissues (hair and bone) of Macaca mulatta (rhesus macaques) for carbon and nitrogen stable isotope dietary analyses. Samples from India, Vietnam, and Burma (Myanmar) were taken, representing both tropical and temperate populations. The delta(13)C values obtained from hair show that the temperate macaques, particularly those from Uttar Pradesh, have a delta(13)C signature that indicates at least some use of C(4) resources, while the tropical individuals have a C(3)-based diet. However, delta(13)C values from bone bioapatite indicate a C(3)-based diet for all specimens and they do not show the C(4) usage seen in the hair of some animals, possibly because bone represents a much longer turnover period than that of hair. The results of delta(15)N analyses grouped animals by geographic region of origin, which may be related to local soil nitrogen values. The greatest variation in delta(15)N values was seen in the specimens from Burma, which may be partly due to seasonality, as specimens were collected at different times of year. We also investigated the relationship between the hair, bone collagen, and bone bioapatite delta(13)C results, and found that they are highly correlated, and that one tissue can be used to extrapolate results for another. However, our results also suggest that hair may pick up discrete feeding traces (such as seasonal usage), which are lost when only bone collagen and bioapatite are examined. This has important implications for dietary reconstructions of archaeological and paleontological populations.

Climatic and non-climatic effects on the δ18O and δ13C compositions of Lake Awassa, Ethiopia, during the last 6.5 ka

A comparison of a 6450 14 Cy rd 18 Oand d 13 C record of authigenic calcite from Lake Awassa, Ethiopia, with other proxy climate records in the area suggests that the lake records long-term regional climate changes. Co-varying and increasing d 18 Oand d 13 C values from B4800 BP suggest an aridification of climate after the early Holocene insolation maximum. After 4000 BP, humid conditions return until after B2800 BP when d 18 Oincreases again, reflecting more arid conditions recorded elsewhere in Ethiopia. In addition to these long-term changes, there are abrupt decreases in both d 18 Ocalcite and d 13 Ccalcite immediately after tephra layers. The likeliest explanation for these abrupt decreases in isotopes is the effect of tephra on the lake’s catchment vegetation. d 18 O, d 13 C and lake-level measurements from Lake Awassa since the 1970s suggest that the lake is currently isotopically sensitive to short-term (annual–decadal) climate change. However, during this period, the catchment has undergone progressive deforestation that may have caused an increase in runoff. Caution is therefore required when reconstructing palaeoclimates as a contemporary lake may not always be a good analogue for lake hydrology in the past. r 2002 Elsevier Science Ltd. All rights reserved.

Large mammal turnover in Africa and the Levant between 1.0 and 0.5 Ma

Abstract Faunal change at the Early-Middle Pleistocene boundary in Europe has long been a topic for discussion. However, analyses of large mammal turnover at this time in Africa have been lacking, largely because of the low number of sites dated to this interval. Recent work, particularly in the last 10 years, has resulted in a much larger published sample of sites and we synthesize these data in this paper. In our multivariate (TWINSPAN) analyses of African and Levantine large mammal faunas we found that localities were subdivided by geographic regions, not by age. There were some small-scale changes with the appearance or extinction of particular taxa, but there was no large-scale turnover such as that seen in Europe. The Levant was included as a possible route for faunal interchange with east Africa, but no similarities were found between these areas. It therefore appears that the modern zoogeographic separation of the Levant and north Africa into the Palaearctic region and sub-Saharan Africa into the African region can be traced back to at least the Early-Middle Pleistocene boundary.

Multi-isotope analysis of the population of the lost medieval village of Auldhame, East Lothian, Scotland

This study is one of only a handful to combine strontium, oxygen, carbon, nitrogen and sulphur isotope data for medieval human remains, in this case from individuals buried in a cemetery in the remote Scottish coastal village of Auldhame, which was abandoned in the 17th century AD. The strontium and oxygen isotope analysis of tooth enamel suggests that the group predominantly comprised a local, static population and thus this allows the examination of the dietary habits of a remote coastal community. The combination of relatively high nitrogen isotope values with relatively low carbon isotope values within bone collagen suggests little marine protein in the diet, which is unusual given the coastal location. The community may have been consuming some freshwater fish or omnivores (pigs fed on animal diets), but also we suggest that the combination of isotope values could be explained by soil improvement methods. Some evidence for soil deepening at the site, and by association manuring, suggests that the consumption of cereals was important to the diet, and may explain the high nitrogen values found in combination with terrestrial carbon isotope values. This combination of dietary isotopes has previously been suggested to be unusual for the medieval period, but we propose it is perhaps more common than originally conceived. As there are few previous multi-isotope studies from Scottish medieval assemblages on this scale, the study provides an opportunity to construct a picture of medieval and early post-medieval life in rural Scotland.

“To the Land or to the Sea”: Diet and Mobility in Early Medieval Frisia

ABSTRACT This study investigated palaeodiet and population mobility in early medieval Frisia through the stable isotope analysis of individuals buried in the fifth–eighth century AD cemetery of Oosterbeintum, a terp site on the northern coast of the Netherlands. The results cast new light on the role of the northern Netherlands in trade and migration in the early medieval period, and have significance for the study of interaction and movement throughout the wider North Sea region. Bone collagen and tooth enamel from humans and animals were analyzed using carbon, nitrogen, oxygen, and strontium isotopes. δ13C and δ15N results indicated that the population had a terrestrial, C3-based diet. High δ15N values were observed in humans and fauna, which are probably related to the terps salt-marsh location. The δ18O and 87Sr/86Sr data revealed a high proportion of non-locals buried at Oosterbeintum, some of whom had probably migrated from regions as distant and varied as Scandinavia and southern England. It is suggested that this immigration may be associated with Frisian maritime trading activities. New data are also presented from a small number of contemporaneous European sites.

Fallow deer (Dama dama dama) management in Roman South-East Britain

This paper presents new carbon, nitrogen and sulphur isotope data for European fallow deer (Dama dama dama) in Roman Britain and discusses results in light of evidence from classical texts, landscape archaeology, zooarchaeology and the limited available samples of metric data. The new isotope data presented here are from Fishbourne Roman Palace (Sussex), two sites on the Isle of Thanet (Kent) and a further two sites in London. In spite of small sample sizes the data make an important contribution to the very limited corpus of scientific research on the species and provide new resolution to the nature of fallow deer movement and management in Roman Britain.

Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities

BackgroundThe dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (Po) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical to cell function, growth and reproduction.ScopeWe asked a group of experts to consider the global issues associated with Po in the terrestrial environment, methodological strengths and weaknesses, benefits to be gained from understanding the Po cycle, and to set priorities for Po research.ConclusionsWe identified seven key opportunities for Po research including: the need for integrated, quality controlled and functionally based methodologies; assessment of stoichiometry with other elements in organic matter; understanding the dynamics of Po in natural and managed systems; the role of microorganisms in controlling Po cycles; the implications of nanoparticles in the environment and the need for better modelling and communication of the research. Each priority is discussed and a statement of intent for the Po research community is made that highlights there are key contributions to be made toward understanding biogeochemical cycles, dynamics and function of natural ecosystems and the management of agricultural systems.

Dead or alive? Investigating long-distance transport of live fallow deer and their body parts in antiquity

The extent to which breeding populations of fallow deer were established in Roman Europe has been obscured by the possibility that the skeletal remains of the species, in particular Dama foot bones and antlers, were traded over long distances as objects in their own right. This paper sets out to refine our understanding of the evidence for the transportation of living and dead fallow deer in Iron Age and Roman Europe. To achieve this, museum archives containing purportedly early examples of Dama antler were searched, with available specimens sampled for carbon, nitrogen and strontium isotope analyses, and compared with data for archaeological fallow deer from across Europe. Importantly, the resulting isotope values can be interpreted in light of new modern baseline data for fallow deer presented here. Together these multi-isotope results for modern and archaeological fallow deer provide a more critical perspective on the transportation of fallow deer and their body parts in antiquity.