Download or read book Spinal Evolution written by Ella Been and published by Springer. This book was released on 2019-08-07 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vertebral spine is a key element of the human anatomy. Its main role is to protect the spinal cord and the main blood vessels. The axial skeleton, with its muscles and joints, provides stability for the attachment of the head, tail and limbs and, at the same time, enables the mobility required for breathing and for locomotion. Despite its great importance, the vertebral spine is often over looked by researchers because: a) vertebrae are fragile in nature, which makes their fossilization a rare event; b) they are metameric (seriated and repeated elements) that make their anatomical determination and, thus, their subsequent study difficult; and c) the plethora of bones and joints involved in every movement or function of the axial skeleton makes the reconstruction of posture, breathing mechanics and locomotion extremely difficult. It is well established that the spine has changed dramatically during human evolution. Spinal curvatures, spinal load transmission, and thoracic shape of bipedal humans are derived among hominoids. Yet, there are many debates as to how and when these changes occurred and to their phylogenetic, functional, and pathological implications. In recent years, renewed interest arose in the axial skeleton. New and exciting finds, mostly from Europe and Africa, as well as new methods for reconstructing the spine, have been introduced to the research community. New methodologies such as Finite Element Analysis, trabecular bone analysis, Geometric Morphometric analysis, and gait analysis have been applied to the spines of primates and humans. These provide a new and refreshing look into the evolution of the spine. Advanced biomechanical research regarding posture, range of motion, stability, and attenuation of the human spine has interesting evolutionary implications. Until now, no book that summarizes the updated research and knowledge regarding spinal evolution in hominoids has been available. The present book explores both these new methodologies and new data, including recent fossil, morphological, biomechanical, and theoretical advances regarding vertebral column evolution. In order to cover all of that data, we divide the book into four parts: 1) the spine of hominoids; 2) the vertebral spine of extinct hominins; 3) ontogeny, biomechanics and pathology of the human spine; and 4) new methodologies of spinal research. These parts complement each other and provide a wide and comprehensive examination of spinal evolution.

Download or read book Evolution of the Hominoid Vertebral Column written by Scott A. Williams and published by . This book was released on 2012-09-28 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a study of the numerical composition of the vertebral column, the central structure of the vertebrate body plan and one that plays an instrumental role in locomotion and posture. Recent models of hominoid vertebral evolution invoke very different roles for homology and homoplasy in the evolution of vertebral formulae in living and extinct hominoids. These processes are fundamental to the emergence of morphological structures and reflect similarity by common descent (homology) or similarity by independent evolution (homoplasy). Although the "short backs," reflecting reduced lumbar regions, of living hominoids have traditionally been interpreted as homologies and shared derived characters (synapomorphies) of the ape and human clade, recent studies of variation in extant hominoid vertebral formulae have challenged this hypothesis. Instead, a "long-back" model, in which primitive, long lumbar regions are retained throughout hominoid evolution and are reduced independently in six lineages of modern hominoids, is proposed. The recently described skeleton of Ardipithecus ramidus is interpreted to support the long-back model. Here, larger samples are collected and placed in a larger phylogenetic context than previous studies. Analyses of over 8,000 mammal specimens, representing all major groups and focusing on anthropoid primates, allow for the reconstruction of ancestral vertebral formulae throughout mammalian evolution and a determination of the uniqueness of hominoid vertebral formulae. This survey, in combination with analyses of intraspecific diversity and interspecific similarity, suggests that reduced lumbar regions are homologous in extant hominoids. Furthermore, hominoid vertebral formulae are unique among primates and relatively unique among mammals in general. Hominins likely evolved five lumbar vertebrae from a short-backed ancestor with an "African ape-like" vertebral profile. By the appearance of Australopithecus, hominins evolved a cranial placement of the diaphragmatic (one that bears a change in articular facet orientation) vertebra, which generates a functionally longer lower spine while maintaining five lumbar vertebrae. In light of these findings, it is proposed that bipedalism evolved in a party arboreal, partly terrestrial African ape-like locomotor context.

Download or read book Evolution and Development of Hominoid Vertebral Transitions written by Allison Machnicki and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The thoracolumbar spine is crucial for understanding primate evolution and the origins and unique adoption of human bipedalism. Both great apes and humans have stabilized their spine with the posterior shift of the transitional vertebra and reduction of non-ribbed lumbar vertebra. There is debate regarding whether these features are homologous or homoplasious, and thus whether bipedalism evolved from a short stiff back like great apes or a longer lumbar column more similar to monkeys and Miocene hominoids. Genetic modification of Hox9 in mice results in the independent modification of rib count and transitional vertebra placemen and genetic modification of Hox11 in mice results in a cranial homeotic shift at the lumbosacral border and position of the sacrum. These transitions mimic the shift of the transitional vertebra and lumbosacral boundary in hominoids. The proposed study addresses important questions that will influence interpretation of differences between extant primates, as well as fossil specimens, by providing a basic understanding for the role of developmental influences on functionally important vertebral features. Since skeletal development is a highly conserved process across tetrapods, conclusions about the development of vertebrae in mice will be broadly applicable to interpretations across mammals. In this analysis, I compare the morphology of the primate transitional vertebra in museum collections and experimentally modified mice. Quantitative, qualitative, and geometric morphometric analyses were conducted on Hox9 and Hox11 modified mice and primate museum specimen thoracic and lumbar columns using micro-CT and 3D surface scanning and a large osteological dataset. In the first part of this dissertation, I analyzed Hox9 and Hox11 modified mice to investigate developmental association or independence of vertebral characters including articular facets, spinous processes, transverse processes, and costal processes. The results of this study indicated that the different Hox clusters have distinct roles on different morphology and in different areas of the vertebral column. Hoxa9, -b9, -c9 and -d9 paralogs had specific and largely separate roles in specifying vertebral identity. Hoxa9 mutations in mice impacted rib placement and count. Hoxb9 and Hoxc9 modifications in isolation affected the placement of the transitional vertebra and the position of spinous process orientation change. Hoxd9 modifications instead affected the sacrocaudal boundary and the number of laterally fused segments contributing of the sacrum. Hoxd11 and combined modifications of Hoxa11 and Hoxd11 resulted in a partial or complete lumbosacral transformation and an anterior shift of the placement of the sacrum within the pelvis. The results of this study indicate that articular facet orientation can be altered independent of costal identity and that articular facet orientation and spinous process orientation shift together whereas transverse process orientation shifts once with the transitional vertebra and a second time over the rib boundary. In the second part of this dissertation, I analyzed a 3D dataset of primate vertebrae to identify characters associated with vertebral column mobility and stiffening. I scanned primate vertebral columns from the 8th thoracic to the 3rd lumbar using either a NextEngine 3D surface scanner or an Artec Space Spider Surface Scanner. From the scans, the vertebrae were scored for thoracic and lumbar characteristics and the angles of the spinous processes were measured to assess spinous process shape to determine which vertebral characters are linked over the articular facet and costal transitions. Additionally, I investigated whether lumbar and sacral count affects sacral position and vertebral entrapment. These data were compared to the Hox mouse models to assess the developmental independence of transitional and costal characters in primates. The results of this study showed that like the Hox mice, articular facet orientation and spinous process orientation were correlated and that there was a shift in transverse process orientation both at the articular facet transition and the costal transition, when they were not in unison. This demonstrates that classic Schultz definitions may not correspond to the developmental boundaries that determine vertebral morphology. Furthermore, humans and chimpanzees displayed a similar cranial shift in sacrum placement to the mice when lumbar count was increased. This has implications for spinal mobility and demonstrates an additional method for either reducing or increasing lumbar entrapment and changing the number of lumbar vertebra contributing to locomotion. In the third part of this dissertation, I analyzed the 3D primate dataset using geometric morphometrics to assess differences between pre- and post-transitional vertebrae within the context of hominoid evolution. The dataset is divided into analyses of the entire section of the vertebral column sampled (T8L2), individual analyses of the transitional vertebra and first two post-transitional vertebrae, individual species analyses of the vertebral column, and finally individual species analyses of individual articular facet surfaces independent of orientation. Overall, differences were seen in shape and orientation across the transitional vertebra between species and this often correlated with locomotor pattern and where mobility or stiffening was needed in the spine. These projects address two important questions: 1) whether patterns of the thoracolumbar and lumbosacral transitions are similar across apes, and 2) the developmental independence of various thoracic, lumbar, and sacral vertebral features. Throughout hominid evolution there has been a posterior shift in the position of the transitional vertebra and there has been an alteration in the placement of the sacrum relative to the iliac crest. The results of these studies show that alteration of Hox genes in mice can result in similar patterns seen in primates and may underlie the anatomical trajectory seen in hominid evolution. Furthermore, the differences in the transition of vertebral characters among great apes suggests that reduction and stiffening of the lumbar column may have evolved independently.

Download or read book Triangulating the Evolution of the Vertebral Column in the Last Common Ancestor written by Burt Alain Rosenman and published by . This book was released on 2008 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primate vertebral skeleton has been studied intensively by morphologists for more than a century and has become a focal point of investigation in biological anthropology. However, several issues regarding vertebral homology and anatomy remain controversial. I collected metric and non-metric data on 392 cercopithecine and hominoid spines to answer the following questions: First, what is the homology of the lumbar transverse process (LTP) in catarrhines? Second, how many lumbar vertebrae do early hominids possess? Third, how do last rib length, LTP width, and sacral width covary in catarrhines? Methods included data collection by caliper measurement as well as statistical tests such as ANCOVA. I conclude that all catarrhine primates share a similar LTP homology, in which the LTP is composed of a rib element ventrally and derivative of the thoracic transverse process dorsally. Based on these findings, I show that the early hominid specimens Sts 14 and Stw 431 possessed a minimum of six functional lumbar vertebrae. In the metric comparisons, I find that humans have relatively short last ribs; that, in addition to their relatively narrow sacra, the African apes have narrow penultimate and ultimate lumbar vertebrae; and that the early hominids Sts 14 and AL 288-1 have the relatively widest LTPs and sacra of the taxa studied. Incorporating all these data, I present a model of hominoid lumbar vertebral evolution in which each of the great apes has independently evolved a short lumbar spine of three to four segments. Therefore, the long lumbar column of early hominids was most likely a primitive retention, and it is not derived as is commonly assumed.

Download or read book An Introduction to Human Evolutionary Anatomy written by Leslie Aiello and published by Academic Press. This book was released on 1990-09-11 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: An anthropologist and an anatomist have combined their skills in this book to provide students and research workers with the essentials of anatomy and the means to apply these to investigations into hominid form and function. Using basic principles and relevant bones, conclusions can be reached regarding the probable musculature, stance, brain size, age, weight, and sex of a particular fossil specimen. The sort of deductions which are possible are illustrated by reference back to contemporary apes and humans, and a coherent picture of the history of hominid evolution appears. Written in a clear and concise style and beautifully illustrated, An Introduction to Human Evolutionary Anatomy is a basic reference for all concerned with human evolution as well as a valuable companion to both laboratory practical sessions and new research using fossil skeletons.

Download or read book Morphological Variation in the Hominoid Vertebral Column written by Lauren Suzanne Stevens and published by . This book was released on 2004 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anatomy and Physiology written by J. Gordon Betts and published by . This book was released on 2013-04-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Embryology of the Human Locomotor System written by Hans K. Uhthoff and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Atlas I want to share with my fellow clinicians the fascina tion I experienced while discovering the marvels of embryonic development. Why haven't these marvels excited me before? I believe that the use of schemata and drawings or photographs of animal embryos, commonly used in textbooks of embryology, simply did not appeal to me as a clinician. Only actual photo graphs of human embryos can establish the bond necessary for interaction. Just imagine the excitement when you find out how many struc tures you can recognize in a 5-week-old embryo, barely measuring 1 cm in length. But our fascination does not stop here. The pro gression of changes taking place during the next 3 weeks is so rapid that at the time when the embryo measures 3 cm, all structures familiar to us are not only easily recognizable, but also already in their anatomical position. How can we hide our amazement when we realize that such a state of perfection is present in an embryo a bit longer than the distal phalanx of our little finger? At 8 weeks the embryonic period ends and the fetal one starts. Although the shape and the relative size of bones, joints, muscles, nerves, and vessels will undergo changes, the basic elements are all in place. This implies that major malformations must develop during the embryonic period.

Download or read book Handbook of Paleoanthropology written by Winfried Henke and published by Springer Science & Business Media. This book was released on 2007-05-10 with total page 2057 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 3-volume handbook brings together contributions by the world ́s leading specialists that reflect the broad spectrum of modern palaeoanthropology, thus presenting an indispensable resource for professionals and students alike. Vol. 1 reviews principles, methods, and approaches, recounting recent advances and state-of-the-art knowledge in phylogenetic analysis, palaeoecology and evolutionary theory and philosophy. Vol. 2 examines primate origins, evolution, behaviour, and adaptive variety, emphasizing integration of fossil data with contemporary knowledge of the behaviour and ecology of living primates in natural environments. Vol. 3 deals with fossil and molecular evidence for the evolution of Homo sapiens and its fossil relatives.

Download or read book The Embryological Development of the Human Vertebral Column written by Deborah Jean Shaner and published by . This book was released on 1986 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surgery of the Spine and Spinal Cord written by Erik van de Kelft and published by Springer. This book was released on 2016-07-04 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers essential guidance on selecting the most appropriate surgical management option for a variety of spinal conditions, including idiopathic problems, and degenerative disease. While the first part of the book discusses the neuroanatomy and biomechanics of the spine, pain mechanisms, and imaging techniques, the second guides the reader through the diagnostic process and treatment selection for disorders of the different regions of the spine, based on the principles of evidence-based medicine. I.e., it clearly explains why a particular technique should be selected for a specific patient on the basis of the available evidence, which is carefully reviewed. The book identifies potential complications and highlights technical pearls, describing newer surgical techniques and illustrating them with the help of images and accompanying videos. Though primarily intended for neurosurgeons, the book will also be of interest to orthopaedic surgeons, specialists in physical medicine, and pain specialists. ​

Download or read book Vertebral Column and Thorax written by A. H. SCHULTZ and published by Karger Medical and Scientific Publishers. This book was released on 1960-10-31 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Skeletal Anatomy of the Newborn Primate written by Timothy D. Smith and published by Cambridge University Press. This book was released on 2020-05-28 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first clearly-illustrated, comparative book on developmental primate skeletal anatomy, focused on the highly informative newborn stage.

Download or read book The Evolution of the Human Head written by Daniel Lieberman and published by Harvard University Press. This book was released on 2011-01-03 with total page 769 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exhaustively researched and years in the making, this innovative book documents how the many components of the head function, how they evolved since we diverged from the apes, and how they interact in diverse ways both functionally and developmentally, causing them to be highly integrated. This integration not only permits the head's many units to accommodate each other as they grow and work, but also facilitates evolutionary change. Lieberman shows how, when, and why the major transformations evident in the evolution of the human head occurred. The special way the head is integrated, Lieberman argues, made it possible for a few developmental shifts to have had widespread effects on craniofacial growth, yet still permit the head to function exquisitely. --

Download or read book The Evolutionary Biology of the Human Pelvis written by Cara M. Wall-Scheffler and published by Cambridge University Press. This book was released on 2020-01-16 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesizes and re-examines the evolution of the human pelvis, which sits at the interface between locomotion and childbirth.

Download or read book Spondylolysis Spondylolisthesis and Degenerative Spondylolisthesis written by Robert Gunzburg and published by Lippincott Williams & Wilkins. This book was released on 2006 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a comprehensive, state-of-the-art clinical reference on spondylolysis, spondylolisthesis, and degenerative spondylolisthesis. Leading experts from the United States, Europe, and Israel present the latest concepts and findings on the biomechanics, clinical presentation, imaging, diagnosis, natural evolution, and conservative and surgical treatment of these vertebral conditions in adults and in children. A major portion of the book focuses on current strategies for surgical treatment in adults.

Download or read book Discovering the Brain written by National Academy of Sciences and published by National Academies Press. This book was released on 1992-01-01 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain ... There is no other part of the human anatomy that is so intriguing. How does it develop and function and why does it sometimes, tragically, degenerate? The answers are complex. In Discovering the Brain, science writer Sandra Ackerman cuts through the complexity to bring this vital topic to the public. The 1990s were declared the "Decade of the Brain" by former President Bush, and the neuroscience community responded with a host of new investigations and conferences. Discovering the Brain is based on the Institute of Medicine conference, Decade of the Brain: Frontiers in Neuroscience and Brain Research. Discovering the Brain is a "field guide" to the brainâ€"an easy-to-read discussion of the brain's physical structure and where functions such as language and music appreciation lie. Ackerman examines: How electrical and chemical signals are conveyed in the brain. The mechanisms by which we see, hear, think, and pay attentionâ€"and how a "gut feeling" actually originates in the brain. Learning and memory retention, including parallels to computer memory and what they might tell us about our own mental capacity. Development of the brain throughout the life span, with a look at the aging brain. Ackerman provides an enlightening chapter on the connection between the brain's physical condition and various mental disorders and notes what progress can realistically be made toward the prevention and treatment of stroke and other ailments. Finally, she explores the potential for major advances during the "Decade of the Brain," with a look at medical imaging techniquesâ€"what various technologies can and cannot tell usâ€"and how the public and private sectors can contribute to continued advances in neuroscience. This highly readable volume will provide the public and policymakersâ€"and many scientists as wellâ€"with a helpful guide to understanding the many discoveries that are sure to be announced throughout the "Decade of the Brain."