Paleodemography of the Carlston Annis (Bt-5) Late Archaic skeletal population

The study presents a demographic assessment of the Carlston Annis (Bt-5) Late Archaic hunting and gathering population recovered from the banks of the Green River in west-central Kentucky. The shell midden habitation and cemetery site originally yielded the remains of 390 individuals. Radiocarbon dates place site occupation between 3,000 and 4,500 y.b.p. The skeletal sample consisted of 354 individuals ranging in age from 7 months in utero to 70 + years. Subadults were aged by seriation of dental and skeletal developmental criteria. Adult ages were determined by the multifactorial summary age method that employed 1) five indicators of adult skeletal age at death, 2) the procedure of age indicator seriation, and 3) differential weighting of age assessments as determined by principal components analysis. Adult sex diagnoses were based on qualitative assessment of pelvic and cranial morphological criteria. The Bt-5 life table analysis yields an E0 of 22.4 years, crude birth of 45, mean family size of 3.3, gross reproductive rate of 2.7, generation length of 26.6 years, and B of .076, indicating a healthy population with a substantial capability to replace succeeding generations. Survivorship profiles and demographic parameters that compare the Carlston Annis (Bt-5) and Indian Knoll (Oh-2) skeletal series are presented. Both populations display type II survivorship curves, with high infant mortality and early onset of elevated mortality rates in adults. Major differences between Bt-5 and Oh-2 demographic parameters concern adult sex ratio and adult age distribution over 30 years. These differences are interpreted to reflect census errors in the Oh-2 demographic reconstruction that were possibly introduced by selective methodological biases and/or taphonomic factors.     

Anatomical, physiological, and epidemiological correlates of the aging process: a confirmation of multifactorial age determination in the Libben skeletal population

Paleodemographic analyses based on estimates of skeletal age at death consistently report high levels of young adult mortality with few individuals living in excess of 50 years. Critics assert these data indicate systematic underaging of adults and justifiably remark that criteria for estimating skeletal age at death may be unreliable, age determinations are too frequently based on one or two criteria alone, and adult paleodemographic age profiles often mimic the age distribution of the modern population from which an age indicator's standards were originally derived. This study reports a series of tests based on well-documented biological aging phenomena that can be used to investigate potential effects of systematic underaging in adults, assuming the skeletal population is of sufficient size to permit such tests. These include patterns of third decade sternal clavicular epiphyseal fusion, multiple age and sex criteria associated with cortical bone dynamics, and fractures known to occur throughout the entire adult ages range. These phenomena are examined here for the Libben site skeletal population where adult age at death was determined by the multifactorial summary age technique. None of the biological criteria reported here were used in the Libben summary age analysis and thus serve as an independent test of accuracy in age determination. In addition, the summary age method has recently been applied to a series of modern skeletons of known age (Todd samples 1 and 2). Age standards for criteria employed with Libben and Todd 1 were identical. Since Todd 1 displayed underaging in older adults, a second Libben age distribution adjusted for Todd 1 bias was generated for comparison. A third Libben adult survivorship profile based on a Coale and Demeny West level 3 mortality experience, considered by some to be a more realistic model for skeletal populations, was produced for comparison. For all criteria examined, original Libben summary ages provided superior concordance with known patterns of biological aging in human populations. While Libben ages adjusted for Todd 1 bias were slightly better in the third decade, both Todd 1 adjusted and Coale and Demeny West level 3 age distributions produced unrealistic patterns of biological aging for individuals greater than 35 years. Implications of these results are discussed.     

The ontogeny of Holocene and Late Pleistocene human postcranial strength

While a wide variety of studies have focused on population variation in adult cross‐sectional properties, relatively little is known about population variation in postcranial robusticity in immature individuals. Furthermore, the age at which the population differences readily detected in adults manifest during growth is also unknown. This research addresses these gaps in our current understanding through the analysis of immature humeral and femoral long bone strength. Cross‐sectional geometry was used to compare the developmental trajectories of diaphyseal strength in Late Pleistocene Neandertal and modern human subadults to a sample of immature humans from seven geographically diverse Holocene populations. Population differences in size‐standardized cross‐sectional properties appear to be systemic and develop very early in ontogeny in the Holocene sample. In many cases, these differences are present before one year of age. In general, the Late Pleistocene fossil samples fit within the range of recent human variation in long bone strength. Population differences detected here are likely related to a combination of factors including activity patterns, genetic propensities, and nutritional status. These results highlight the complex mosaic of processes that result in adult postcranial robusticity, and suggest that further exploration of the developmental interplay between intrinsic and extrinsic influences on skeletal robusticity will likely enhance our understanding of adult postcranial morphology. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.     

Long bone growth variation among Arikara skeletal populations

Long bone growth variation among skeletal samples has had limited application to ecological studies of archaeological groups, in spite of its well-known sensitivity to health and nutritional status. In this study we examine long bone growth variation among ten samples of Arikara skeletal groups, all located in the Middle Missouri subarea of South Dakota and ranging in time from A.D. 1600 to 1832. The samples are analyzed by variant, an archaeological taxonomic unit below Tradition. Children's long bones between about 0.5 and 11.9 years of age were analyzed by means of regression using the model, bone length =b₀ + b₁ (age) + b₂ (log₁₀ age). The three variants, Extended Coalescent, Postcontact Coalescent, and Disorganized Coalescent, differ from one another with regard to health and nutritional status. Extended Coalescent groups probably experienced periods of undernutrition due to unfavorable climatic conditions prevailing at the time. Postcontact Coalescent groups experienced more favorable health and nutrition due to improved climatic conditions and introduction of the horse. Disorganized Coalescent groups were exposed to undernutrition and high levels of morbidity, due to introduction of epidemic diseases, depopulation, and intertribal conflict. Analysis of slopes shows significant heterogeneity among variants for humerus, radius, and tibia, but not femur. In general, the Postcontact Coalescent is characterized by slighter greater rates of increase with age and longer bone lengths for each age than is Extended Coalescent. Disorganized Coalescent exhibits lower rates of increase, particularly in later childhood, with shorter bone lengths in late childhood. Disorganized Coalescent also presents longer radius and humerus lengths than the other two variants in early childhood, an unexpected finding. This may be partly, but not entirely, explained by differential bone response to stress along the lines of maturity gradients.     

Influence of early qualitative feed restriction and environmental temperature on long bone development of broiler chickens

This investigation was carried out to study the influence of early qualitative feed restriction and environmental rearing temperature on long bone development in broiler. Energy and protein restriction reduced femur width and humerus weight, but did not affect tibia parameters. Broilers kept at cold environmental temperature showed reduced femur, tibia and humerus length and tibia weight, but the calculated density was not affected by rearing temperature. These findings suggest that qualitative feed restriction and environmental temperature influenced the normal long bone growth; however, bone weight/bone length index (calculated density) was not affected by rearing temperature.     

Bone microstructure of Lewisuchus admixtus Romer, 1972 (Archosauria,Dinosauriformes)

Lewisuchus admixtus is a basal dinosauriform coming from Late Triassic outcrops of NW Argentina. Although this taxon was recently anatomically restudied, histological data is still wanting. The microstructure of the long bones (femur and two tibie) reveals a relatively fast rate of growth, comparable with that seen in other basal Dinosauriformes and basal dinosaurs. Cortical bone is comprised of fibro-lamellar complex in one femur and tibia, but parallel-fibered matrix are observed in the other tibia. The secondary remodelling of bone is poor and there is not growth marks. The vascularization is relatively dense, longitudinal, laminar and reticular. There are some features that indicate slowdown of the growth at late age of the specimens. The fast growth of L. admixtus implies a relatively high metabolic rate. This is probably related with environmental conditions.     

Relative growth rates of predator and prey dinosaurs reflect effects of predation

Hadrosaurs grew rapidly, and quantifying their growth is key to understanding life-history interactions between predators and prey during the Late Cretaceous. In this study, we longitudinally sampled a sequence of lines of arrested growth (LAGs) from an essentially full-grown hadrosaur Hypacrosaurus stebingeri (MOR 549). Spatial locations of LAGs in the femoral and tibial transverse sections of MOR 549 were measured and circumferences were calculated. For each bone, a time series of circumference data was fitted to several stochastic, discrete growth models. Our results suggest that the femur and the tibia of this specimen of Hypacrosaurus probably followed a Gompertz curve and that LAGs reportedly missing from early ontogeny were obscured by perimedullary resorption. In this specimen, death occurred at 13 years and took approximately 10-12 years to reach 95 per cent asymptotic size. The age at growth inflection, which is a proxy for reproductive maturity, occurred at approximately 2-3 years. Comparisons with several small and large predatory theropods reveal that MOR 549 grew faster and matured sooner than they did. These results suggest that Hypacrosaurus was able to partly avoid predators by outgrowing them.     

Response of the longitudinal growth of cranium and long bones to early weaning in the rabbit

To study the problem whether the growth rates of the cranium and of long bones are different from one another, in 13 age groups of 5 rabbits each three distances of the skull (SSO-SL, SSO-P and N-NSA) and the length of the femur, tibia and calcaneus were measured. Following the early weaning of the rabbits (41/2 weeks), the increase of all measurements was strongly delayed for about one week. Thereafter, during a two weeks' period a typical catch-up growth was observed. From these results the conclusion was drawn that the growth rates of cranium and long bones do not differ from each other, and that a temporary deficiency of food intake affects intramembranous bone growth and cartilaginous growth in a similar way.     

Infant and child diet in Neolithic hunter-fisher-gatherers from Cis-Baikal, Siberia: intra-long bone stable nitrogen and carbon isotope ratios

Analysis of stable nitrogen and carbon isotopes (δ(15) N and δ(13) C) from subadults and adults allows for assessment of age-related dietary changes, including breastfeeding and weaning, and adoption of an adult diet. In one of the first studies of hunter-fisher-gatherer subadults from Eurasia, three Neolithic (8,800-5,200 calBP) mortuary sites from southwestern Siberia are analyzed to evaluate hypothesized differences in weaning age between Early versus Late Neolithic groups. An intra-individual sampling methodology is used to compare bone formed at different ages. Collagen samples (n = 143) from three different growth areas of long bones-the proximal metaphysis, diaphysis, and distal metaphysis-were obtained from 49 subadults aged birth to 10 years. In infants (birth to 3 years, n = 23) contrasting the δ(15) N values of the metaphysis, which contains newer bone, to the δ(15) N values of the diaphysis, which contains older bone, permits a more precise determination of breastfeeding-weaning status. In Early and Late Neolithic groups breast milk was the major protein source until the age of 2-3 years. However, there are differences in the age of weaning completion and duration: Early Neolithic groups weaned their infants at a later age and over a shorter amount of time. Differences may have affected infant morbidity and mortality, and female fecundity and inter-birth intervals. Stable isotope values in older subadults (4-10 years, n = 26) do not differ from adults suggesting the absence of age-based food allocation.     

Deciduous enamel defects and caries susceptibility in a prehistoric Ohio population

Clinical studies of the relationship between developmental enamel defects and caries susceptibility have often produced conflicting results. This has been due in part to a failure to distinguish between different types of defects. Studies of this association in prehistoric populations have been rare. The complete deciduous dentitions of 57 subadults from the Libben site, a large Late Woodland cemetery in Ottawa County, Ohio, were selected for analysis. Defects were classified as either hypoplasias (deficiencies in matrix apposition) or hypocalcifications (deficiencies in mineralization) and were graded for severity. The presence or absence of carious lesions was recorded for each tooth. Results indicate a strong positive relationship between hypocalcifications and caries susceptibility. The elevated caries susceptibility of hypocalcified teeth may be related to high levels of magnesium or altered enamel microcrystallite orientation within these teeth. Variations in the frequency of hypocalcifications may partially explain differences in caries rates that have been observed in different prehistoric populations.     

The analysis of fractures in skeletal populations with an example from the Libben site,Ottowa County,Ohio

A quantitative approach to the analysis of long-bone fractures in skeletal populations is presented. These kinds of data are shown to be valuable in interpreting various behavioral aspects of the population. An example of application is provided for the Libben population. Data from this group show that the overall fracture rate was high (there is a 45% chance of a long-bone fracture in any single individual) but lower than the rates observed in nonhuman primates by almost an order of magnitude when data are adjusted for years of risk. The data for Libben also suggest that traumatic child abuse was not practiced, that most fractures occur as a consequence of accident, that fracture risk was highest in the 10–25 and 45 + age categories, that care of patients was enlightened and skillful in this group, and that chance of fracture is largely determined by accumulated years of risk in the population (r = 0.97).     

Technical note: calculation of age at formation of radiopaque transverse lines

A simple method for determining the age of an individual at the time of radiopaque transverse (Harris) line formation is presented. To use this method, only two measurements are required: total bone length and distance of line to nearest bone end; these are put into formulae that calculate the percent of total bone growth when the line appeared. The result of this calculation is compared with tables of percent bone growth per year (one to 16 years in females and one to 18 years in males) to arrive at estimations of age at line formation. Since these tables are presented for the femur, tibia, humerus, and radius, this technique can be used on any one of the major long bones exhibiting lines.     

Epiphyseal union at the innominate and lower limb in a modern Portuguese skeletal sample, and age estimation in adolescent and young adult male and female skeletons

This study documents the timing of epiphyseal union at the innominate, femur, tibia, and fibula in a sample of modern Portuguese skeletons. The sample was taken from the Lisbon documented skeletal collection and it is comprised of 57 females and 49 males between the ages of 9 and 25. Individuals are mostly representative of the middle-to-low socioeconomic segment of the early 20th century Lisbon population. A total of 18 anatomical locations were examined for epiphyseal union using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. Results show that females are ahead of males by 1-2 years and provide similar age ranges for the stages of union than previous studies. Some variations between studies can be explained by methodological differences between dry bone and radiographic observations. However, a review of the literature indicates that socioeconomic status of a given population seems to be of decisive importance to the rate of ossification and most of the differences in skeletal maturation across studies and populations can probably be ascribed to different levels of social and economic development of the societies in which the individuals lived. Although the effects of socioeconomic status in skeletal maturation are greater during childhood than in adolescence, as to make the timing of epiphyseal union a reliable estimate of age at death, they are not negligible and age estimates should take into account the likely socioeconomic status of the individual, whose remains are under examination.     

Comparison of diaphyseal growth between the Libben population and the Hamann-Todd chimpanzee sample

The differences in limb lengths and proportions between humans and chimpanzees are widely known. Humans have relatively shorter forelimbs and longer hind limbs than chimpanzees. Humans have a longer period of long bone formation than chimpanzees. Recent advances in estimating age-at-death in chimpanzees from their dentition have allowed us to reexamine long bone growth in chimpanzees using their skeletal remains and compare it with similar data for humans. A chronological normalization procedure allowing direct interspecific comparison of long bone growth is presented. The preadult chimpanzee sample (n = 43) is from the Hamann-Todd Osteological Collection from the Cleveland Museum of Natural History. All human specimens (n = 202) are from the late Woodland Libben Population currently housed at Kent State University. Relying on these cross-sectional data, we conclude that both species elongate their femora at similar absolute (length per unit time) but different relative (length relative to normalized dental age) rates. The species differ in the absolute growth rate of the humerus but share a common normalized rate of growth. Forelimb segment proportion differences between species are due to differential elongation rates of the segments. Hind limb diaphyseal proportions are the same in both species, which suggests that changes in segment length are proportional. Therefore, alternative developmental mechanisms exist in these closely related species which can produce changes in limb length. © 1996 Wiley-Liss, Inc.     

Female biological resiliency: Differential stress response by sex in human remains from ancient Nubia

This research presents male-female differences in stress response evidenced in human remains from the Medieval site of Kulubnarti in Sudanese Nubia. This analysis is unique in that a direct comparison of subadult males and females is rarely possible using archaeological remains. Rather, such analyses invariably rely on evidence of subadult differences retained in adult (sexable) skeletons. In the case of Kulubnarti, natural mummification has made it possible to measure sex-specific differences among subadults as well as adults following five avenues of investigation: 1) mortality, 2) growth and development, 3) enamel hypoplasia, 4) cribra orbitalia, and 5) cortical bone maintenance. A comparison of mean life expectancy (eox) values for males and females aged 10–55+ years revealed a consistent pattern of greater female survivorship, particularly in childhood (age 10 category) where female life expectancy exceeds that of males by 19%. Measures of growth and development, enamel hypoplasia, cribra orbitalia, and cortical bone loss were subsequently used to test a hypothesis of greater female resiliency based on the mortality data. Male-female differences in skeletal maturation are pronounced with male skeletal ages averaging a significant 2.9 years below their dental age. Females show no significant differences with an average skeletal age 0.75 years ahead of dental age. Males begin hypoplasia formation one year earlier than females and, prior to age four, average 18% more hypoplasias (p<0.05). Also, by age 8, males have on average more than twice the frequency of cribra orbitalia (p<0.05). In contrast to their consistent pattern of reduced childhood stress, adult females lose significantly more cortical bone than their male counterparts and have less cortical bone across the adult age range. Nevertheless, females outnumber males of all ages with a sex-ratio below but parallel to that observed in modern populations. The rapid age-related reduction in males relative to females, even in old age, suggests a continuing female resiliency in spite of their greater rate of osteopenia and may reflect a reproductive advantage to the population through heightened female survival and adaptability.     

Developmental appearance of matrix GLA protein during calcification in the rat

A marked dissociation has been observed between the timed accumulation in calcified tissues of two related vitamin K-dependent proteins, bone Gla protein (BGP) and the recently discovered matrix Gla protein (MGP). In long bone diaphyses, total levels of MGP were essentially equivalent in newborn, juvenile, and adult rats. In agreement with previous studies, BGP levels were only 5% of adult levels in newborn rat bones and increased to 90% of adult levels by 19 days of age. Similar results were obtained from the analysis of the longitudinal distribution of MGP and BGP in 14-day-old rat tibia, a bone in which new mineral is added rapidly at both growth plates. Again, MGP was essentially at the same level in the regions nearest the growth plates as in the midshaft while BGP levels were 10-fold lower in the regions nearest the growth plates. These differences in the timed accumulation of MGP and BGP in calcifying tissues indicate that MGP could function earlier in bone formation than does BGP. To further characterize the MGP antigen in bone, extracts from newborn and adult rat bones were chromatographed by gel filtration over Sephacryl S-200. All of the antigen extracted by formic acid and most of the antigen subsequently extracted by guanidine HCI emerged at the position expected for the 79-residue MGP. There was a significant difference in the fraction of total MGP which was extracted by guanidine HCI in newborn (50%) and adult (20%) bone. The radioimmunoassay for rat MGP which was developed for these studies employs rabbit antibody directed against calf MGP and rat MGP for standards and radioiodinated tracer. This assay has a sensitivity of 0.1 ng and does not detect rat or calf BGP.     

Brief communication: Prenatal and early postnatal stress exposure influences long bone length in adult rat offspring

Stress during the prenatal and early postnatal periods (perinatal stress, PS) is known to impact offspring cognitive, behavioral, and physical development, but effects on skeletal growth are not clear. Our objective was to analyze effects of variable, mild, daily PS exposure on adult offspring long bone length. Twelve pregnant rat dams were randomly assigned to receive variable stress from gestational days 14–21 (Prenatal group), postpartum days 2–9 (Postnatal), both periods (Pre–Post), or no stress (Control). Differences in adult offspring tibia and femur length were analyzed among treatment groups. Mean tibia length differed among groups for males (P = 0.016) and females (P = 0.009), and differences for femur length approached significance for males (P = 0.051). Long bone length was shorter among PS‐exposed offspring, especially those exposed to postnatal stress (Postnatal and Pre–Post groups). Results persisted when controlling for nose–tail length. These differences might reflect early stunting that is maintained in adulthood, or delayed growth among PS‐exposed offspring. This study suggests that PS results in shorter long bones in adulthood, independently of effects on overall body size. Stunting and growth retardation are major global health burdens. Our study adds to a growing body of evidence suggesting that PS is a risk factor for poor linear growth. Am J Phys Anthropol 149:307–311, 2012. © 2012 Wiley Periodicals, Inc.     

Dental indicators of stress and reduced age at death in prehistoric Native Americans

Considerable evidence supports the hypothesis that developmental enamel defects represent stress-induced growth disruptions. In this investigation, the relationship between different kinds of enamel defects and age at death is examined in the prehistoric Libben population from Ottawa County, Ohio. The sample consisted of the permanent dentitions of 143 individuals. Defects were classified based on the criteria of the Developmental Defects of Enamel (DDE) Index. The multifactorial age at death determinations of Lovejoy and coworkers (1977) were used in this analysis. Results reveal a significantly lower mean age at death for individuals with enamel defects vs. individuals with normal teeth. This pattern was clearly present for all defect types examined. No significant differences by sex were detected. The age-at-death distribution for individuals with normal teeth approximated the normal curve. The modal value was reached in the 35–40 year age class. The age-at-death distribution for individuals with enamel defects showed two peaks. The mode occurred in the 15–20 year age class, and the second, lower peak occurred in the 30–35 year age class. The early mortality of individuals with enamel defects may be related to biological damage to the immune system during prenatal or postnatal development. © 1996 Wiley-Liss, Inc.     

Ultrastructural changes in bones of the senescence-accelerated mouse (SAMP6): a murine model for senile osteoporosis

SAMP6, a substrain of senescence-accelerated mice, was developed as an animal model for senile osteoporosis. In the present study, we investigated the bone morphology, together with serum calcium and bone mineral density (BMD) in SAMP6 and age-matched normal mice SAMR1. We did not find any significant differences between SAMR1 and SAMP6 at 1 month of age with regard to the serum compositions and bone morphology. As compared with SAMR1, BMD, the femoral weight, femoral calcium and phosphorus levels were significantly reduced in SAMP6 at 2 and 5 months of age. The number of osteoblasts in trabecular bones was also significantly reduced. Swollen mitochondria and myelin-like structures were found in osteoblasts and osteocytes of SAMP6 mice at 2 and 5 months of age. There was a greater proportion of resting surface and less forming surface in the femoral endosteal surfaces of SAMP6 mice. The amount of trabecular bone in the lumbar vertebra and the distal metaphysis of the femur was reduced. The number of the mast cells in bone marrow of the tibia significantly increased in SAMP6 mice. These findings indicate that the lower bone mass in SAMP6 was due to the reduction in osteoblast formation and suggested that mast cells in bone marrows play a role in the pathogenesis of senile osteoporosis.     

Effect of carbimazole induced hypothyroidism and thyroxine replacement on the growth of the long bones in albino rats of different age groups

To evaluate the effect of carbimazole induced hypothyroidism and thyroxine replacement, on the growth of long bones of albino rats of different age groups. Experimental albino rats were developed with carbimazole and carbimazole plus thyroxine for a period of six weeks. At the end of the experiment the animals were sacrificed, fixed and processed to demonstrate the bony and cartilaginous parts. The ulna and tibia of both sides were measured for intact bone length & diameter and the data compared. The reduction in length and circumference observed, at the end of experiment, in ulna was 10.89%, & 11.94% and in tibia it was 12.52%, 14.81% in carbimazole treated group respectively, while in carbimazole plus thyroxin treated group the reduction in length & circumference of ulna was 1.37% & 1.88% and in tibia it was 1.86% & 3.08% respectively. They were compared to their age matched controls. The reduction in length and circumference in ulna was 5.58% & 6.25% and 6.42% and 5.88% in tibia respectively among the carbimazole treated animals while in the carbimazole plus thyroxine treated animals the reduction was only 0.63% and 3.12% in ulna and 0.91% and 1.06% in tibia respectively. The results show that hypothyroidism and its replacement therapy affects the endochondral as well as periosteal bone growth and results in reduction in length as well as circumference of long bones.