Maria Teschler-Nicola

The genetic history of Ice Age Europe

Modern humans arrived in Europe ~45,000 years ago, but little is known about their genetic composition before the start of farming ~8,500 years ago. We analyze genome-wide data from 51 Eurasians from ~45,000-7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3–6% to around 2%, consistent with natural selection against Neanderthal variants in modern humans. Whereas the earliest modern humans in Europe did not contribute substantially to present-day Europeans, all individuals between ~37,000 and ~14,000 years ago descended from a single founder population which forms part of the ancestry of present-day Europeans. A ~35,000 year old individual from northwest Europe represents an early branch of this founder population which was then displaced across a broad region, before reappearing in southwest Europe during the Ice Age ~19,000 years ago. During the major warming period after ~14,000 years ago, a new genetic component related to present-day Near Easterners appears in Europe. These results document how population turnover and migration have been recurring themes of European pre-history.

Direct dating of Early Upper Palaeolithic human remains from Mladec.

The human fossil assemblage from the Mladeč Caves in Moravia (Czech Republic) has been considered to derive from a middle or later phase of the Central European Aurignacian period on the basis of archaeological remains (a few stone artefacts and organic items such as bone points, awls, perforated teeth), despite questions of association between the human fossils and the archaeological materials and concerning the chronological implications of the limited archaeological remains. The morphological variability in the human assemblage, the presence of apparently archaic features in some specimens, and the assumed early date of the remains have made this fossil assemblage pivotal in assessments of modern human emergence within Europe. We present here the first successful direct accelerator mass spectrometry radiocarbon dating of five representative human fossils from the site. We selected sample materials from teeth and from one bone for 14C dating. The four tooth samples yielded uncalibrated ages of ∼31,000 14C years before present, and the bone sample (an ulna) provided an uncertain more-recent age. These data are sufficient to confirm that the Mladeč human assemblage is the oldest cranial, dental and postcranial assemblage of early modern humans in Europe and is therefore central to discussions of modern human emergence in the northwestern Old World and the fate of the Neanderthals.

Investigation of Sr isotope ratios in prehistoric human bones and teeth using laser ablation ICP-MS and ICP-MS after Rb/Sr separation

87Sr/86Sr isotope ratio measurements on bone and teeth tissue were used in order to assess prehistoric human migration. Microstructural changes of skeletal remains caused by post mortem influences (especially dissolving and re-crystallization), may lead to erratic results, if invasive techniques (e.g. digestion and liquid nebulization ICP-MS) are used. Therefore, Rb/Sr separation performed on digested sample solutions prior to ICP-MS measurements was optimized and we developed a procedure to separate Sr from Rb quantitatively to enable a fast and reliable interference free measurement of Sr isotope ratios. As main goal, we have applied LA-ICP-MS on transversal bone cross sections on diagenetically altered and non-altered areas making use of both high lateral resolution and isotope ratio capabilities. Sr isotope ratio measurements on bone material were performed with an instrumental precision between 0.1 and 0.2% RSD by LA-ICP-MS. We could reveal mineralized phases (Brushit) histomorphologically within the cross section of cortical femur samples. Those crystallites showed a significantly increased amount of Rb. The results indicate that these products are exogenous. In addition, human teeth were analyzed for their 87Sr/86Sr isotope ratio primarily to investigate possible differences in enamel and dentine. LA-ICP-MS led to excellent results and shows RSD of isotope ratio measurements of about 0.1–0.2% on both enamel and dentine. One specific individual (from Neolithic Asparn/Schletz) was investigated using the prior methods and showed homogeneous Sr isotope ratios in dentine and bone, while the Sr isotopic composition in enamel was significantly different. This result demonstrates a possible migration of this individual during early childhood.

The Ice Man’s diet as reflected by the stable nitrogen and carbon isotopic composition of his hair

Establishing the diets of ancient human populations is an integral component of most archaeological studies. Stable isotope analysis of well‐preserved bone collagen is the most direct approach for a general assessment of paleodiet. However, this method has been limited by the scarcity of well‐preserved skeletal materials for this type of destructive analysis. Hair is preserved in many burials, but is often overlooked as an alternative material for isotopic analysis. Here we report that the stable carbon and nitrogen isotope values for the hair of the 5200 year‐old Ice Man indicates a primarily vegetarian diet, in agreement with his dental wear pattern. Whereas previous investigations have focused on bone collagen, the stable isotope composition of hair may prove to be a more reliable proxy for paleodiet reconstruction, particularly when skeletal remains are not well preserved and additional archaeological artifacts are unavailable.—Macko, S. A., Lubec, G., Teschler‐Nicola, M., Andusevich, V., Engel, M. H. The Ice Mans diet as reflected by the stable nitrogen and carbon isotopic composition of his hair. FASEB J. 13, 559–562 (1999)

Community differentiation and kinship among Europe’s first farmers

Community differentiation is a fundamental topic of the social sciences, and its prehistoric origins in Europe are typically assumed to lie among the complex, densely populated societies that developed millennia after their Neolithic predecessors. Here we present the earliest, statistically significant evidence for such differentiation among the first farmers of Neolithic Europe. By using strontium isotopic data from more than 300 early Neolithic human skeletons, we find significantly less variance in geographic signatures among males than we find among females, and less variance among burials with ground stone adzes than burials without such adzes. From this, in context with other available evidence, we infer differential land use in early Neolithic central Europe within a patrilocal kinship system.

Strontium isotope ratio measurements in prehistoric human bone samples by means of high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS)

This paper explores the suitability and application range of a commercially available high-resolution ICP-mass spectrometer (Finnigan MAT Element) in determining strontium isotope ratios of human bone samples. Any paleoanthropological interpretation of such samples requires a highly accurate isotopic ratio determination with a precision of at least 0.1% relative standard deviation (RSD). Thus, optimum instrument operating parameters such as sampling time, scan duration, and instrumental bias factors including mass bias and deadtime, were investigated in an initial step. The instrument itself was used without modification but equipped with a commercial microconcentric nebulizer. All experiments were performed under clean room conditions with filtered (class 10.000), temperature controlled, and excess pressured air. Complementary mathematical correction methods like deadtime and mass bias corrections, allowed the achievement of a87Sr/86Sr isotope ratio precision below 0.03% (RSD for n=5). Compared with the certified NIST SRM 987 Strontium Carbonate (Isotopic) value (0.71034±0.00026), our 87Sr/86Sr isotopic ratio revealed a 0.7103±0.0002 match. This optimized procedure was performed on 7000-year-old human skeleton samples from a Neolithic settlement in Asparn/Schletz, Lower Austria, to determine their stable strontium isotope ratio. Specific isotope patterns thereby shed light on the provenance of single individuals.

Age- and Sex-Dependent Cancellous Bone Changes in a 4000y BP Population

We studied cancellous bone loss in a 4000y BP population, using several methods designed to detect age-related changes, in order to investigate the pattern of cancellous bone loss in this ancient population and to compare the results deriving from different methods used on identical specimens. We used 10-mm sections of fourth lumbar vertebral bodies and left femoral necks of 18 individuals of both sexes with estimated ages from 20 to 60 years of a 4000y BP bronze-age population. Stereoscopic photographs were used for three-dimensional analysis and trabecular number (TN) counting. After embedding, the following parameters were measured in different image analysis systems using plane parallel block samples: bone mineral density (BMD) in water by DEXA, and by evaluation of standardized radiographic images; fractional bone volume (BV/TV) in backscattered electron images of the trabecular surface layer and in optical images of trabeculae in a surface-stained layer; and trabecular bone pattern factor (TBPf) in the latter images. There was a high correlation between the results of morphological methods for measuring fractional bone volume. Reasonable correlations were found between the x-ray photon methods and poor correlations between these and the morphological methods. These poor correlations may be due to the diagenetic substitution occurring in archaeological skeletons, which would strongly influence x-ray-based density measurements. However, all the methods demonstrated that the most dramatic loss of quantity and quality in cancellous bone occurred in females between 40 and 60 years.(ABSTRACT TRUNCATED AT 250 WORDS)

CANCELLOUS BONE STRUCTURE IN THE GROWING AND AGING LUMBAR SPINE IN A HISTORIC NUBIAN POPULATION

Abstract. There is abundant data on cancellous bone in the aging human spine, but little relating to the growing vertebral cancellous bone in childhood and adolescence. The purpose of this study was to map vertebral cancellous bone in a growth and age series of historic skeletal samples and to make comparisons with data published on recent material. Lumbar vertebral bodies were collected from 65 skeletons (0–60 years) from a medieval Nubian population. Ethnohistoric information was collected to interpret conditions that might have influenced bone structure and metabolism. The cancellous bone was studied three dimensionally, using stereophotography and scanning electron microscopy and morphometrically by performing a semiautomatic structural analysis on digitized backscattered electron images of polymethacrylate-embedded material. The cancellous bone structure in the children consisted mainly of a densely packed, uniform network of small rodlike trabeculae. The greatest bone volume fraction with small, more platelike trabeculae was observed during adolescence. In young adults, larger platelike trabeculae were present in the central zone and smaller trabeculae in the superior and inferior zones, as described for modern skeletal material. Structural changes associated with aging were observed much sooner than in modern man. By the estimated age of approximately 50–60 years, the predominant architectural elements were slender rarified rods in both sexes. The ethnohistorical data suggest that this was essentially a black African population of physically active peasants, not likely to suffer Vitamin D insufficiency or deficient calcium intake. Thus an earlier onset of the biological age changes in cancellous bone found in modern populations was probably prevalent.

Enhanced methods for assessment of the trace element composition of Iron Age bone

Modern, ultra-trace, analytical methods, coupled with magnetic sector ICP-MS (HR-ICP-MS), were applied to the determination of a large suite of major and trace elements in Iron Age bones. The high sensitivity and un-paralleled signal-to-noise characteristics of HR-ICP-MS enabled the accurate measurement of Ag, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, La, Li, Mg, Mn, Ni, P, Pb, Pt, Rb, Sr, U, V, and Zn in small bone sections (<75 mg). Critically, the HR-ICP-MS effectively addressed molecular interferences, which would likely have compromised data generated with quadrupole-based ICP-MS instruments. Contamination and diagenetic alteration of ancient bone are grave concerns, which if not properly addressed, may result in serious misinterpretation of data from bone archives. Analytical procedures and several chemical and statistical methods (Principal Components Analysis - PCA) were studied to assess their utility in identifying and correcting bone contamination and diagenetic alteration. Uncertainties in bone (femur) sampling were characterized for each element and longitudinal variation was found to be the dominant source of sampling variability. However the longitudinal variation in most trace elements levels was relatively modest, ranging between 9 and 17% RSD. Bone surface contamination was evaluated using sequential acid leaching. Calcium-normalized metal levels in brief, timed, dilute nitric acid leaches were compared with similarly normalized interior core metal levels to assess the degree of surface enrichment. A select group of metals (Mn, Co, Ni, Ag, Cd, and Pt) were observed to be enriched by up to a factor of 10 in the bone surface, indicating that that these elements may have a higher contamination component. However, the results of sequential acid leaching experiments indicated that the single acid leaching step was effective in removing most surface-enriched contaminants. While the leaching protocol was effective in removing contaminants associated with the bone surface, there remained potentially significant residual levels of soil-sourced contaminant tracers within the leached bone. To address this issue a mathematical procedure, based on metal/aluminum ratios, was developed to correct-for the soil-contaminant metal pools. Soil correction fractions for the primary anthropogenically mobilized metals evaluated were greatest for Pb (13.6%) followed by As (4.4%), Ag (3.9%), and Cd (0.94%). Although median soil corrections were typically low, many samples did require a much larger correction, thus both bone cleaning and soil corrections may be necessary to realize accurate endogenous bone elemental data. The results of the PCA analysis were remarkably consistent with outcomes from the chemical and elemental ratio protocols evaluated in the study, and suggest that loadings on certain factors will be helpful in screening for soil-biased samples and in identifying diagenetically altered bone. Application of these contamination evaluation and correction tools was made possible by the high-quality, multi-element, datasets produced by HR-ICP-MS. Large variations in bone core concentrations between the 80 Iron Age specimens examined were observed for all the primary trace elements and in many of the supporting elements, even after correction for major contaminant components.

Sex Determination Using Tooth Dimensions

Among the many parameters used in studies of prehistoric skeletal series, two are fundamental prerequisites for any statistical analysis: the age at death and the sex of an individual. Various demographic, biological or pathological features can be studied when these parameters are known. Biological age at death assessments are needed for estimating mortality rates, which subsequently have implications for the possible conclusions to be drawn about living conditions, nutritional status, epidemiology, social stratification etc. in prehistoric societies.