The Implications of Variation in Late Pleistocene Levantine Crania for Understanding the Pattern of Human Evolution.

The inspiration for this dissertation comes from the variability in a sample of Late Pleistocene fossil human crania found in the Southern Levant, in present day Israel. This sample (n=13) is comprised of both Neandertals from Tabun and Amud, and the remains from Skhul and Qafzeh that are considered predecessors of modern humans. Many authors describe the heterogeneity of the Levantine sample as unusual, greater than what modern populations could be expected to exhibit, and many believe they represent groups of different human species. The focus of this study is on whether the magnitude of Levantine variation is really unusual – because this has significance for understanding the pattern of human evolution and identifying past species. The issue is addressed in a statistical, comparative context: 113 crania at 6 museums and laboratories in 5 countries were examined. To demonstrate the Levantine sample variation is really caused by taxonomic differences, at the minimum the Levantines should exhibit a greater magnitude of variation than expected in a comparable modern population of mixed ancestry from a confined geographic area and limited time span. This would indicate that the Levantine variation is not from species mixture; it involved a mixture of human populations. This null hypothesis is tested by comparing the Levant sample’s non-metric cranial variation with the cranial variation in 100 mixed-ancestry medieval crania from the Pannonian Plain (fourth to eighth century A.D.). Dichotomous, binomial responses were collected for 67 traits. The mean and variance of ratios of the scores describe the heterogeneity versus homogeneity. One thousand samples of n=13 were randomly drawn with replacement from the Pannonian data. The fossil Levantine sample was compared to the resampled Pannonian distribution to test whether the magnitude and variance of the Levant data are expected within it. The results show that the magnitude of variation in the Levantine sample is not unusual when compared to the Pannonian sample, and the null hypothesis of admixture of different populations cannot be refuted. These results are strongly supported by the recent ongoing advances in the study of ancient and modern nDNA, showing significant Neandertal mixture in the Levant.Ph.D.AnthropologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89653/1/radovcic_1.pd

New insights on the Neanderthal knee-joint loading environment from the endostructural configuration of the patellae from Krapina, Croatia

The Neanderthal patella is anteroposteriorly thicker and shows more symmetric articular facets associated with higher angles than in recent humans. While it does not appear to be a close relationship between the degree of patellar facet asymmetry and the configuration of the distal femur, which is similar among Neanderthals, fossil and recent humans, the functional implications of such differences are still debated. By using micro-focus X-ray tomography (isotropic voxel size range: 24-50 μm), we characterized the endostructural pattern of six Neanderthal patellae representing five individuals from the OIS 5e site of Krapina, Croatia, and compared the results to those from a sample of 31 patellae representing 22 adult recent humans of various origins and socio-economic patterns. For the cortico-trabecular complex and trabecular thickness, the Neanderthal values fall within the human range of variation. Conversely, in Krapina cancellous bone density (BV/TV) in the medial aspect is higher, and the degree of anisotropy in the inferior aspect is lower than measured in humans. Also, while a bone reinforcement in the lateral and superior aspects is present in humans, in Krapina it is only found laterally. Interestingly, as commonly observed in humans, in Krapina the BV/TV is higher in the left patella. The only other evidence available from an adult Neanderthal patella, Regourdou 1 (France, OIS 4), does not fully overlap the average signal recorded in Krapina. Endostructural differences of the patella thus reveal differing knee-joint loading environments between Neanderthals and humans, as well as inter-individual variation likely age-, sex- and/or physical activity-related

Dental cementum virtual histology of Neanderthal teeth from Krapina (Croatia, 130–120 kyr): an informed estimate of age, sex and adult stressors

The evolution of modern human reproductive scheduling is an aspect of our life history that remains vastly uncomprehended. The present work aims to address this gap by validating a non-destructive cutting-edge methodology to infer adult life-history events on modern teeth with known life history and then applying it to fossil specimens. We use phase-contrast synchrotron X-ray microtomography to visualize the dental cementum of 21 specimens: nine contemporary humans; 10 Neanderthals from Krapina (Croatia, 130–120 kyr); one Neolithic Homo sapiens from Ajmana (Serbia); and one Mesolithic H. sapiens from Vlasac (Serbia). We were able to correctly detect and time (root mean square error = 2.1 years; R2 = 0.98) all reproductive (menarche, parturition, menopause) and other physiologically impactful events in the modern sample. Nonetheless, we could not distinguish between the causes of the events detected. For the fossil specimens, we estimated age at death and age at occurrence of biologically significant events. Finally, we performed an exploratory analysis regarding possible sexual dimorphism in dental cementum microstructure, which allowed us to correctly infer the sex of the Neolithic specimen, for which the true value was known via DNA analysis

Homo naledi, a new species of the genus Homo

Homo naledi es una especie previamente desconocida de homínido extinto descubierta dentro de la Cámara Dinaledi del sistema de cuevas Rising Star, en el Cradle of Humankind, Sudáfrica. Esta especie se caracteriza por tener una masa corporal y estatura similar a las poblaciones humanas de cuerpo pequeño, pero un volumen endocraneal pequeño similar al de los australopitecos. La morfología craneal de H. naledi es única, pero se asemeja más a las especies tempranas de Homo, incluyendo Homo erectus, Homo habilis o Homo rudolfensis. Aunque primitiva, la dentición es generalmente pequeña y simple en su morfología oclusal. H. naledi presenta adaptaciones manipulativas de la mano y la muñeca similares a las humanas. También exhibe un pie y miembro inferior similares a los humanos. Estos aspectos humanos se contrastan en el postcráneo con un tronco, hombro, pelvis y fémur proximal más primitivos o similares a los australopitecos. Representando al menos 15 individuos con la mayoría de los elementos esqueléticos repetidos múltiples veces, esta es la mayor colección de una sola especie de homínidos descubierta en África.National Geographic SocietyThe National Research Foundation of South Africa (WARF)The Palaeontological Scientific TrustLyda Hill FoundationWisconsin Alumni Research Foundation (WARF)Texas A and M UniversityDepto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu