Reconstructing patterns of domestication in reindeer using 3D muscle attachment areas.

The use of reindeer has been a crucial element in the subsistence strategies of past Arctic and Subarctic populations. However, the spatiotemporal occurrence of systematic herding practices has been difficult to identify in the bioarchaeological record. To address this research gap, this study proposes a new virtual anthropological approach for reconstructing habitual physical activity in reindeer, relying on the protocols of the "Validated Entheses based Reconstruction of Activity" (VERA) method. Following blind analytical procedures, we focused on eight muscle attachment sites ("entheses") in 36 reindeer free ranging in the wild, 21 specimens in captivity (zoo), and eight racing reindeer (habitual runners). Importantly, our analyses accounted for the effects of variation by subspecies, sex, age, and estimated body size. Our results showed clear differences across activity groups, leading to the development of discriminant function equations with cross-validated accuracies ranging from approximately 88 to 100%. The reliability of our functions was additionally confirmed using a blind test involving six zoo individuals not included in the initial dataset. Our findings support the use of the proposed approach for identifying domestication-related activities in zooarchaeological contexts, introducing a valuable tool for locating suspected domestication hotspots and elucidating the nature of past human-reindeer interactions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12520-023-01910-5.

Tendons and ligaments of the Rangifer tarandus metapodial and hoof.

Rangifer tarandus, the northern species including both reindeer and caribou, is a pillar of northern ecosystems and the lives of northern peoples. As the only domestic cervid, reindeer are important not only to the herders and hunters who presently interact with them, but also to zooarchaeologists and palaeontologists tracing their histories. Unfortunately, limited anatomical information on Rangifer tarandus muscles is available beyond descriptions of the large muscle groups. The lower limb and hoof in particular is poorly documented. This is problematic, as this important body part has the potential to be informative in zooarchaeological analyses of habitual activity, especially in regards to historical animal health, movement, and habitual activity. Better understanding of the hoof can additionally be useful to herders and veterinarians seeking to provide veterinary care for living animals. This study has used dissections and comparisons of the reindeer hoof with other domestic ungulates to document both the common and unique structures in Rangifer tarandus hooves, including the presence and attachment points of these structures. As these structures have proved unique, especially in regards to the dewclaw, it is important that other ungulates not be used exclusively in the analysis of Rangifer tarandus remains.

Influence of captivity and selection on limb long bone cross-sectional morphology of reindeer.

The emergence of pastoralism and animal husbandry has been a critical point in the history of human evolution. Beyond profound behavioural changes in domesticated animals compared to wild ones, characterising the morphological changes associated with domestication process remains challenging. Because reindeer (Rangifer tarandus) can be considered to still be in the early phases of the domestication process, the study of modern populations provides a unique opportunity to examine the impact of captivity and selective breeding on skeletal changes. In this work, we investigated the morphological changes in long limb bone cross-sections using 137 wild and domestic reindeer individuals bred in free-range, in captivity or used for racing and pulling. The shape and shaft cortical thickness of the six long limb bones (i.e., humerus, radioulna, metacarpal, femur, tibia and metatarsal) were measured using a 2D-geometric morphometrics approach taking into account subspecies, sex, body mass and lifestyle differences. These bones are important to understanding functional morphological changes because they can provide information on feeding and locomotor behaviours, as well as on body propulsion and weight bearing. Apart from the effects of taxonomy, etho-ecology and sex, we have found that captivity and selection induced important variations in the size and body mass of modern reindeer. Our results also showed that patterns of variation in cortical bone thickness of long limb bone cross-sections were strongly impacted by body mass and human-imposed restrictions in roaming. This demonstrates that bone cross-sections can provide information on changes in locomotor, reproductive and feeding behaviours induced by the domestication process. These results are valuable not only for (paleo) biologists studying the impact of captivity and selection in ungulates but also for archaeologists exploring the origins of domestication and early herding strategies.

Identifying early stages of reindeer domestication in the archaeological record: a 3D morphological investigation on forelimb bones of modern populations from Fennoscandia.

Reindeer herding probably developed during the Late Iron Age onwards and is still an important part of the subsistence and culture of many peoples in northern Eurasia. However, despite the importance of this husbandry in the history of these Arctic people, the period and place of the origin as well as the spread of domestic reindeer is still highly debated. Besides the existence of different breeding methods in these territories, identifying domesticated individuals in the archaeological record is complicated because reindeers are considered to still be in the early phases of the domestication process. Indeed, the traditional morphological markers used in zooarchaeology to decipher the domestication syndrome are hardly perceptible in these early stages. In this work, we propose solutions for identifying domestic reindeer bones using 3D geometric morphometrics on isolated elements from the long bones of the forelimb (i.e. humerus, radio-ulna and metacarpal). These bones are important to understand both the feeding behaviour and the mobility of reindeer, and the potential effect of load-carrying or draught in the case of domestic reindeer. We analysed 123 modern specimens from Fennoscandia, including the two interbreeding subspecies currently present in these territories: mountain reindeer (Rangifer tarandus tarandus) and forest reindeer (R.t. fennicus); and where the sex and the lifestyle were known (i.e. free-ranging, racing or draught and captive individuals). A good level of discrimination between the size and shape variables of the bones of the forelimb was found among both subspecies and sexes. Moreover, individuals bred in captivity had smaller bone elements and a thinner and more slender morphology than free-ranging individuals. This demonstrates that the long bones of the forelimb can provide information on changes in feeding and locomotor behaviour prompted by the domestication process, like control and/or reduction of mobility and food of individual reindeer by humans. This also demonstrates that analysis in 3D geometric morphometrics is useful in detecting reindeer incipient domestication markers. Our results can be used by archaeologists to trace the early stages of domestication from fossil reindeer remains, and aid in reconstructing the socio-economic changes of past Arctic populations over time.

Identification of working reindeer using palaeopathology and entheseal changes.

OBJECTIVE: This paper explores the potential of analyzing pathological lesions and entheseal changes in the identification of working reindeer. METHODS: The skeletons of 26 modern working reindeer from Siberia and Northern Finland are analyzed for pathological lesions and entheseal changes. RESULTS: Working results in elevated frequencies of pathological lesions, specifically joint disease in cervical and thoracic vertebrae, humeri, os coxae and proximal phalanges. Entheseal scores indicate the intensified use of shoulder flexors and extensors, and possibly elbow, hip and knee flexors and extensors in working reindeer. CONCLUSION: Patterns of skeletal changes can be used in the identification of working reindeer from the past. SIGNIFICANCE: This study provides first evidence that pathological lesions and entheseal changes can be used to assess draught and cargo use of reindeer. Therefore, the methods presented in this study provide an opportunity to scrutinize past reindeer herding practices, reindeer domestication and human-reindeer cooperation. LIMITATIONS: Methods need to be applied with caution due to the multifactorial etiologies of pathological lesions and entheseal changes. SUGGESTIONS FOR FUTURE RESEARCH: We suggest that in future studies, these methods are applied to archaeological material accompanied by osteometric and contextual analyses.

Do bone geometric properties of the proximal femoral diaphysis reflect loading history, muscle properties, or body dimensions?

OBJECTIVES: The aim of this study was to investigate activity-induced effects from bone geometric properties of the proximal femur in athletic vs nonathletic healthy females by statistically controlling for variation in body size, lower limb isometric, and dynamic muscle strength, and cross-sectional area of Musculus gluteus maximus. METHODS: The material consists of hip and proximal thigh magnetic resonance images of Finnish female athletes (N = 91) engaged in either high jump, triple jump, soccer, squash, powerlifting, endurance running or swimming, and a group of physically active nonathletic women (N = 20). Cross-sectional bone geometric properties were calculated for the lesser trochanter, sub-trochanter, and mid-shaft of the femur regions. Bone geometric properties were analyzed using a general linear model that included body size, muscle size, and muscle strength as covariates. RESULTS: Body size and isometric muscle strength were positively associated with bone geometric properties at all three cross-sectional levels of the femur, while muscle size was positively associated with bone properties only at the femur mid-shaft. When athletes were compared to nonathletic females, triple jump, soccer, and squash resulted in greater values in all studied cross-sections; high jump and endurance running resulted in greater values at the femoral mid-shaft cross-section; and swimming resulted in lower values at sub-trochanter and femur mid-shaft cross-sections. CONCLUSIONS: Activity effects from ground impact loading were associated with higher bone geometric values, especially at the femur mid-shaft, but also at lesser and sub-trochanter cross-sections. Bone geometric properties along the femur can be used to assess the mechanical stimuli experienced, where ground impact loading seems to be more important than muscle loading.

The effect of age and body composition on body mass estimation of males using the stature/bi-iliac method.

The stature/bi-iliac breadth method provides reasonably precise, skeletal frame size (SFS) based body mass (BM) estimations across adults as a whole. In this study, we examine the potential effects of age changes in anthropometric dimensions on the estimation accuracy of SFS-based body mass estimation. We use anthropometric data from the literature and our own skeletal data from two osteological collections to study effects of age on stature, bi-iliac breadth, body mass, and body composition, as they are major components behind body size and body size estimations. We focus on males, as relevant longitudinal data are based on male study samples. As a general rule, lean body mass (LBM) increases through adolescence and early adulthood until people are aged in their 30s or 40s, and starts to decline in the late 40s or early 50s. Fat mass (FM) tends to increase until the mid-50s and declines thereafter, but in more mobile traditional societies it may decline throughout adult life. Because BM is the sum of LBM and FM, it exhibits a curvilinear age-related pattern in all societies. Skeletal frame size is based on stature and bi-iliac breadth, and both of those dimensions are affected by age. Skeletal frame size based body mass estimation tends to increase throughout adult life in both skeletal and anthropometric samples because an age-related increase in bi-iliac breadth more than compensates for an age-related stature decline commencing in the 30s or 40s. Combined with the above-mentioned curvilinear BM change, this results in curvilinear estimation bias. However, for simulations involving low to moderate percent body fat, the stature/bi-iliac method works well in predicting body mass in younger and middle-aged adults. Such conditions are likely to have applied to most human paleontological and archaeological samples.

The relationship between loading history and proximal femoral diaphysis cross-sectional geometry.

OBJECTIVES: We investigated the relationship between loading history and bone biomechanical properties used in physical activity reconstructions. These bone properties included bone bending and torsional strength (J), cortical area (CA), the direction of the major axis (theta angle), and element shape ratios determined from cross sections of standardized bone length. In addition, we explored the applicability of anatomically determined cross sections. METHODS: Our material consisted of hip and proximal thigh magnetic resonance images of Finnish female athletes (N = 91) engaged in high-jump, triple-jump, endurance running, swimming, power-lifting, soccer and squash; along with a group of active non-athlete individuals (N = 20). We used regression analysis for size-adjustment, and the extracted residuals were then used to compare differences in the bone properties between groups. RESULTS: We found that triple-jumpers, soccer players, and squash players had the greatest values in CA and J, swimmers and non-athletes had the smallest, whereas high-jumpers, power-lifters, and endurance runners exhibited interim values. No between-the-group differences in element shape ratios or theta angles were found. We found that influences of activity were similar regardless of whether standardized length or anatomically determined cross sections were used. CONCLUSIONS: Extreme (triple-jump) and directionally inconsistent loading (soccer and squash) necessitate a more robust skeleton compared to directionally consistent loading (high-jump, power-lifting, and endurance running) or non-impact loading (swimming and non-athletes). However, not all of these relationships were statistically significant. Thus, information gained about physical activity using bone properties is informative but limited. Accounting for the limitations, the method is applicable on fragmented skeletal material as anatomically determined cross sections can be used.

The cross-sectional area of the gluteus maximus muscle varies according to habitual exercise loading: Implications for activity-related and evolutionary studies.

Greater size of the gluteus maximus muscle in humans compared to non-human primates has been considered an indication of its function in bipedal posture and gait, especially running capabilities. Our aim was to find out how the size of the gluteus maximus muscle varies according to sports while controlling for variation in muscle strength and body weight. Data on gluteus maximus muscle cross-sectional area (MCA) were acquired from magnetic resonance images of the hip region of female athletes (N=91), and physically active controls (N=20). Dynamic muscle force was measured as counter movement jump and isometric knee extension force as leg press. Five exercise loading groups were created: high impact (triple-jumpers and high-jumpers), odd impact (soccer and squash players), high magnitude (power-lifters), repetitive impact (endurance runners) and repetitive non-impact (swimmers) loadings. Individuals in high impact, odd impact or high-magnitude loading groups had greater MCA compared to those of controls, requiring powerful hip extension, trunk stabilization in rapid directional change and high explosive muscle force. Larger body size and greater muscle strength were associated with larger MCA. An increase in dynamic force was associated with larger MCA, but the strength of this relationship varied with body weight. Thus, gluteal adaptation in humans promotes powerful lower limb movements required in sprinting and rapid changes in direction, as well as maintenance and stabilization of an erect trunk which also provides a platform for powerful motions of the upper limbs. These movements have likely evolved to facilitate food acquisition, including hunting.

Suspected tuberculosis in an early 17th-century northern Finnish mummy-A computed tomography case study.

The custom of burying deceased members of the elite beneath church floors was common in 17th-18th-century Finland. This practice is responsible for the mummification of the remains of an early 17th-century vicar of Kemi parish, Nikolaus Rungius. Computed tomography performed on his remains revealed a possible tuberculous infection in his spine. The purpose of this paper is to further elaborate on findings in support of this diagnosis. Whether Vicar Rungius had tuberculosis is not only interesting considering his personal history, but also in terms of the history of tuberculosis in Northern Finland where the first systematically recorded cases date back to the 18th century.

Entheseal changes and pathological lesions in draught reindeer skeletons - Four case studies from present-day Siberia.

Draught use and being ridden often result in typical pathological patterns in animal skeletons. Moreover, physical activity patterns may be reflected in bone biomechanical properties and entheseal changes at muscle attachment sites. This paper presents the pathologies and entheseal changes observed in four draught and/or racing reindeer skeletons against information on their life histories and discusses the probability of linking the observed changes to their use. The results of this study are a useful point of comparison to researchers working on reindeer and other species of draught animals. However, our results also emphasize that entheseal changes and many pathologies have multifactorial etiologies and that interpretation of skeletal change patterns is not straightforward, even when there is information on the life history of the animal and its complete skeleton can be examined.

Stature and body mass estimation from skeletal remains in the European Holocene.

Techniques that are currently available for estimating stature and body mass from European skeletal remains are all subject to various limitations. Here, we develop new prediction equations based on large skeletal samples representing much of the continent and temporal periods ranging from the Mesolithic to the 20th century. Anatomical reconstruction of stature is carried out for 501 individuals, and body mass is calculated from estimated stature and biiliac breadth in 1,145 individuals. These data are used to derive stature estimation formulae based on long bone lengths and body mass estimation formulae based on femoral head breadth. Prediction accuracy is superior to that of previously available methods. No systematic geographic or temporal variation in prediction errors is apparent, except in tibial estimation of stature, where northern and southern European formulae are necessary because of the presence of relatively longer tibiae in southern samples. Thus, these equations should bebroadly applicable to European Holocene skeletal samples.

The relationship between musculoskeletal stress markers and biomechanical properties of the humeral diaphysis.

Musculoskeletal stress markers (MSM) at entheses and bone biomechanical properties are used in activity reconstructions. The effect of physical activity on bone biomechanical properties is well established but the relative role of physical activity on MSM is less well known. In this article, it is hypothesized that the same causal mechanisms should affect MSM development as those responsible for bone biomechanical properties. Further, there should be a correlation between MSMs and bone cross-sectional properties as both are considered to reflect physical activity. This was tested using three skeletal samples: early 20th century Finnish (Helsinki) and two medieval English (Blackgate and York) populations. Torsional/average bending rigidity (J) for four cross-sectional locations at 80, 65, 50, and 35% of humeral length from the distal end was calculated and pectoralis major, teres major, and deltoid were scored for MSM. Correlations between MSM and size-standardized J were significant for many comparisons, although they were stronger in males than in females, especially on the right side. In ANOVAs, sample was found to be a significant influence on the right side in both sexes. Using an aggregated MSM score, covariance between J and high MSM scores was again stronger in males. Covariance between J and MSM was found both at cross-sectional locations under muscle insertions and at more distant locations, demonstrating both direct and general effects of muscular loadings applied to diaphyses. Thus, the two types of skeletal markers appear to be related to similar underlying mechanical factors, but effects may also be sex- and sample-specific.

Cross sectional properties of the human radial tuberosity.

This study examines the cross sectional shape and biomechanical properties of the radial bone shaft at mid-radial tuberosity (RT) musculoskeletal marker (MSM). This information will provide insight into factors affecting bone modelling at muscle insertions. Radial shaft cross-sectional properties at radial tuberosity area (RTA) have not been previously studied. The material consists of 54 male skeletons derived from autopsies performed during the 1920s and 1930s and housed at the Central Natural History Museum, University of Helsinki. The age, sex and occupation of these individuals are known. We applied a pQCT (peripheral quantitative computed tomography) scan on the mid-site of the radial tuberosity to investigate the cross-sectional shape, the bone mineral density (BMD) and biomechanical properties. Our results indicate that bone modelling does not produce increased wall thickness or BMD at the RT site. Additionally we noticed that aging and physical activity affect the biomechanics of the RT and that the bone distribution at mid-RT is adapted to accommodate the biceps brachii muscle pull. We also found a clear association between RTA and biomechanical properties of mid-RT cross section.