A preliminary assessment of the thoracic remains of the El Sidrón Neandertals (Asturias, Spain)

Resumen del póster presentado en: 3rd Annual Meeting of the European Society for the study of Human Evolution, 19-21 September 2013, Vienna/AustriaPeer reviewe

Differential growth and development of the upper and lower human thorax

The difficulties in quantifying the 3D form and spatial relationships of the skeletal components of the ribcage present a barrier to studies of the growth of the thoracic skeleton. Thus, most studies to date have relied on traditional measurements such as distances and indices from single or few ribs. It is currently known that adult-like thoracic shape is achieved early, by the end of the second postnatal year, with the circular cross-section of the newborn thorax transforming into the ovoid shape of adults; and that the ribs become inclined such that their anterior borders come to lie inferior to their posterior. Here we present a study that revisits growth changes using geometric morphometrics applied to extensive landmark data taken from the ribcage. We digitized 402 (semi) landmarks on 3D reconstructions to assess growth changes in 27 computed tomography-scanned modern humans representing newborns to adults of both sexes. Our analyses show a curved ontogenetic trajectory, resulting from different ontogenetic growth allometries of upper and lower thoracic units. Adult thoracic morphology is achieved later than predicted, by diverse modifications in different anatomical regions during different ontogenetic stages. Besides a marked increase in antero-posterior dimensions, there is an increase in medio-lateral dimensions of the upper thorax, relative to the lower thorax. This transforms the pyramidal infant thorax into the barrel-shaped one of adults. Rib descent is produced by complex changes in 3D curvature. Developmental differences between upper and lower thoracic regions relate to differential timings and rates of maturation of the respiratory and digestive systems, the spine and the locomotor system. Our findings are relevant to understanding how changes in the relative rates of growth of these systems and structures impacted on the development and evolution of modern human body shapeCGL2012-37279 (Spanish Ministry for Economy and Competition) Fyssen-foundation (http://www.fondationfyssen.fr

Late subadult ontogeny and adult aging of the human thorax reveals divergent growth trajectories between sexes

Sexual dimorphism is an important feature of adult thorax morphology, but when and how sex-related differences in the ribcage arise during ontogeny is poorly known. Previous research proposed that sex-related size differences in the nasal region arise during puberty. Therefore, we explore whether ribcage sexual dimorphism also arises at that time and whether this sexual dimorphism is maintained until old age. We measured 526 (semi)landmarks on 80 CT-based human ribcage reconstructions, on individuals ranging from 7 to 65 year-old. The 3D coordinates were submitted to the Procrustes superimposition and analyzed. Our results show that the trajectories of thorax size and shape between sexes diverge at around 12 years of age, and continue slightly diverging until old age. The differential ontogenetic trends cause adult male ribcages to become deeper, shorter, and wider than female. Our results are consistent with the evidence from the cranial respiratory system, with the development of sexual dimorphism probably related to changes in body composition during puberty combined with changes in the reproductive system

The first Neanderthal remains from an open-air Middle Palaeolithic site in the Levant

The late Middle Palaeolithic (MP) settlement patterns in the Levant included the repeated use of caves and open landscape sites. The fossil record shows that two types of hominins occupied the region during this period - Neandertals and Homo sapiens. Until recently, diagnostic fossil remains were found only at cave sites. Because the two populations in this region left similar material cultural remains, it was impossible to attribute any open-air site to either species. In this study, we present newly discovered fossil remains from intact archaeological layers of the open-air site 'Ein Qashish, in northern Israel. The hominin remains represent three individuals: EQH1, a nondiagnostic skull fragment; EQH2, an upper right third molar (RM3); and EQH3, lower limb bones of a young Neandertal male. EQH2 and EQH3 constitute the first diagnostic anatomical remains of Neandertals at an open-air site in the Levant. The optically stimulated luminescence ages suggest that Neandertals repeatedly visited 'Ein Qashish between 70 and 60 ka. The discovery of Neandertals at open-air sites during the late MP reinforces the view that Neandertals were a resilient population in the Levant shortly before Upper Palaeolithic Homo sapiens populated the region

Spino-pelvic alignment: An evolutionary perspective

Presentación en: 4rd Annual Meeting of the European Society for the study of Human Evolution (Florence, Italy ; 18-20 September 2014)During human evolution the spinal curvature as well as pelvic and sacral orientation have changed dramatically, from a very small pelvic incidence and spinal curvatures in non human hominoids to large curvatures in modern humans. This change was accompanied by a dramatic shift of the line of gravity and C7 plumb line. In this work we will describe the spino-pelvic adjustments to upright posture and bipedality of four major hominin groups; Australopithecines, H. erectus, Neandertals and H. sapiens.Peer reviewe

Analysis of Qafzeh 27-A New Adult Fossil from Qafzeh, Israel

Publication de résumé de colloque dans American Journal of Physical Anthropolog

Students as anatomy near-peer teachers: a double-edged sword for an ancient skill

Abstract Background A near-peer instructors (NPI) program was designed for 1st year medical students who successfully finished the Anatomy course, in order to develop their didactic ability and teaching skills, mostly for cadaver dissection. Methods Graduates of the training program were administered a voluntary survey at the end of the program, annually. Best graduates of the training program were offered a NPI position in the next academic year. They were evaluated by the first-year students, at the end of the Anatomy block. Results In a debriefing questionnaire at the end of the NPI training, on the five-point Likert scale (1 = lowest to 5 = highest), the overall rating ranged from 3.63 in 2013 to 3.71 in 2015. Learning prosection and anatomy demonstration skills scored on average from 4.30 to 4.36, respectively. The NPIs were then evaluated by first-year students at the end of the next year’s Anatomy block. On the Likert scale, the average score of NPIs ranged from 4.10 in 2014 to 4.75 in 2016, on the par with the general satisfaction score for the professional preclinical teachers during the same period (which ranged from 3.80 to 4.26). Conclusions It is suggested that students as near-peer instructors can make a valuable contribution to the teaching faculty, especially in a new medical school

Differential Growth and Development of the Upper and Lower Human Thorax

The difficulties in quantifying the 3D form and spatial relationships of the skeletal components of the ribcage present a barrier to studies of the growth of the thoracic skeleton. Thus, most studies to date have relied on traditional measurements such as distances and indices from single or few ribs. It is currently known that adult-like thoracic shape is achieved early, by the end of the second postnatal year, with the circular cross-section of the newborn thorax transforming into the ovoid shape of adults; and that the ribs become inclined such that their anterior borders come to lie inferior to their posterior. Here we present a study that revisits growth changes using geometric morphometrics applied to extensive landmark data taken from the ribcage. We digitized 402 (semi) landmarks on 3D reconstructions to assess growth changes in 27 computed tomography-scanned modern humans representing newborns to adults of both sexes. Our analyses show a curved ontogenetic trajectory, resulting from different ontogenetic growth allometries of upper and lower thoracic units. Adult thoracic morphology is achieved later than predicted, by diverse modifications in different anatomical regions during different ontogenetic stages. Besides a marked increase in antero-posterior dimensions, there is an increase in medio-lateral dimensions of the upper thorax, relative to the lower thorax. This transforms the pyramidal infant thorax into the barrel-shaped one of adults. Rib descent is produced by complex changes in 3D curvature. Developmental differences between upper and lower thoracic regions relate to differential timings and rates of maturation of the respiratory and digestive systems, the spine and the locomotor system. Our findings are relevant to understanding how changes in the relative rates of growth of these systems and structures impacted on the development and evolution of modern human body shape. © 2013 Bastir et al.Funding: CGL2012-37279 (Spanish Ministry for Economy and Competition) Fyssen-foundation (http://www.fondationfyssen.fr).Peer Reviewe

Monumental megalithic burial and rock art tell a new story about the Levant Intermediate Bronze "Dark Ages".

The Intermediate Bronze Age (IB) in the Southern Levant (ca. 2350-2000 BCE) is known as the "Dark Ages," following the collapse of Early Bronze urban society and predating the establishment of the Middle Bronze cities. The absence of significant settlements and monumental building has led to the reconstruction of IB social organization as that of nomadic, tribal society inhabiting rural villages with no central governmental system. Excavation in the Shamir Dolmen Field (comprising over 400 dolmens) on the western foothills of the Golan Heights was carried out following the discovery of rock art engravings on the ceiling of the central chamber inside one of the largest dolmens ever recorded in the Levant. Excavation of this multi-chambered dolmen, covered by a basalt capstone weighing some 50 tons, revealed a secondary multi-burial (of both adults and children) rarely described in a dolmen context in the Golan. Engraved into the rock ceiling above the multi-burial is a panel of 14 forms composed of a vertical line and downturned arc motif. 3D-scanning by structured-light technology was used to sharpen the forms and revealed the technique employed to create them. Building of the Shamir dolmens required a tremendous amount of labor, architectural mastery, and complex socio-economic organization well beyond the capacity of small, rural nomadic groups. The monumental megalithic burial of the Shamir dolmens indicates a hierarchical, complex, non-urban governmental system. This new evidence supports a growing body of recent criticism stemming from new discoveries and approaches that calls for rethinking our views of the Levantine IB "Dark Ages.

Thorax kinematics and the reconstruction of body models in hominin evolution

Póster en: 4rd Annual Meeting of the European Society for the study of Human Evolution (Florence, Italy ; 18-20 September 2014)Peer reviewe