Seeman, Morris, and Summers misrepresent or misunderstand the arguments we have made, as well as their own previous work. Here, we correct these inaccuracies. We also reiterate our support for ...hypothesis-driven and evidence-based research.
Anterolateral ligament anatomy: a comparative anatomical study Ingham, Sheila Jean McNeill; de Carvalho, Rogerio Teixeira; Martins, Cesar A. Q. ...
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA,
04/2017, Letnik:
25, Številka:
4
Journal Article
Recenzirano
Purpose
Some anatomical studies have indicated that the anterolateral ligament (ALL) of the knee is distinct ligamentous structure in humans. The purpose of this study is to compare the lateral ...anatomy of the knee among human and various animal specimens.
Methods
Fifty-eight fresh-frozen knee specimens, from 24 different animal species, were used for this anatomical study. The same researchers dissected all the specimens in this study, and dissections were performed in a careful and standardized manner.
Results
An ALL was not found in any of the 58 knees dissected. Another interesting finding in this study is that some primate species (the prosimians: the red and black and white lemurs) have two LCLs.
Conclusion
The clinical relevance of this study is the lack of isolation of the ALL as a unique structure in animal species. Therefore, precaution is recommended before assessing the need for surgery to reconstruct the ALL as a singular ligament.
In a previous study, we introduced the template method as a means of enlarging the Australopithecus afarensis postcranial sample to more accurately estimate its skeletal dimorphism. Results indicated ...dimorphism to be largely comparable to that of Homo sapiens. Some have since argued that our results were biased by artificial homogeneity in our Au. afarensis sample. Here we report the results from inclusion of 12 additional, newly reported, specimens. The results are consistent with those of our original study and with the hypothesis that early hominid demographic success derived from a reproductive strategy involving male provisioning of pair-bonded females.
The human pisiform is a small, nodular, although functionally significant, bone of the wrist. In most other mammals, including apes and Australopithecus afarensis, pisiforms are elongate. An ...underappreciated fact is that the typical mammalian pisiform forms from two ossification centers. We hypothesize that: (i) the presence of a secondary ossification center in mammalian pisiforms indicates the existence of a growth plate; and (ii) human pisiform reduction results from growth plate loss. To address these hypotheses, we surveyed African ape pisiform ossification and confirmed the presence of a late‐forming secondary ossification center in chimpanzees and gorillas. Identification of the initial ossification center occurs substantially earlier in apes relative to humans, raising questions concerning the homology of the human pisiform and the two mammalian ossification centers. Second, we conducted histological and immunohistochemical analyses of pisiform ossification in mice. We confirm the presence of two ossification centers separated by organized columnar and hypertrophic chondrocyte zones. Flattened chondrocytes were highly mitotic, indicating the presence of a growth plate. Hox genes have been proposed to play a fundamental role in growth plate patterning. The existence of a pisiform growth plate presents an interesting test case for the association between Hox expression and growth plate formation, and could explain the severe effects on the pisiform observed in Hoxa11 and Hoxd11 knockout mice. Consistent with this hypothesis, we show that Hoxd11 is expressed adjacent to the pisiform in late‐stage embryonic mouse limbs supporting a role for Hox genes in growth plate specification. This raises questions concerning the mechanisms regulating Hox expression in the developing carpus.
The substantial fossil record for Australopithecus afarensis includes both an adult partial skeleton Afar Locality (A.L.) 288-1, “Lucy” and a large simultaneous death assemblage (A.L. 333). Here we ...optimize data derived from both to more accurately estimate skeletal size dimorphism. Postcranial ratios derived from A.L. 288-1 enable a significant increase in sample size compared with previous studies. Extensive simulations using modern humans, chimpanzees, and gorillas confirm that this technique is accurate and that skeletal size dimorphism in A. afarensis was most similar to that of contemporary Homo sapiens . These data eliminate some apparent discrepancies between the canine and skeletal size dimorphism in hominoids, imply that the species was not characterized by substantial sexual bimaturation, and greatly increase the probability that the reproductive strategy of A. afarensis was principally monogamy.
DEVELOPMENTAL BIOLOGY AND HUMAN EVOLUTION Lovejoy, C. Owen; McCollum, Melanie A; Reno, Philip L ...
Annual review of anthropology,
01/2003, Letnik:
32, Številka:
1
Journal Article
Recenzirano
Our understanding of developmental biology burgeoned during the last decade.
This review summarizes recent advances, provides definitions and explanations
of some basic principles, and does so in a ...way that will aid anthropologists in
understanding their profound implications. Crucial concepts, such as
developmental fields, selector and realizator genes, cell signaling mechanisms,
and gene regulatory elements are briefly described and then integrated with the
emergence of skeletal morphology. For the postcranium, a summary of events from
limb bud formation, the appearance of anlagen, the expression of
Hox
genes, and the fundamentals of growth plate dynamics are briefly summarized. Of
particular importance are revelations that bony morphology is largely
determined by pattern formation, that growth foci such as physes and synovial
joints appear to be regulated principally by positional information, and that
variation in these fields is most likely determined by
cis
-regulatory
elements acting on restricted numbers of anabolic genes downstream of selectors
(such as
Hox
). The implications of these discoveries for the
interpretation of both contemporary and ancient human skeletal morphology are
profound. One of the most salient is that strain transduction now appears to
play a much reduced role in shaping the human skeleton. Indeed, the entirety of
"Wolff's Law" must now be reassessed in light of new knowledge
about pattern formation. The review concludes with a brief discussion of some
implications of these findings, including their impact on cladistics and
homology, as well as on biomechanical and morphometric analyses of both ancient
and modern human skeletal material.
Proximal femoral morphology and associated musculature are of special relevance to the understanding of hominoid locomotor systems. Knowledge of bone–muscle correspondence in extant hominoids forms ...an important comparative basis for inferring structure–function relationships in fossil hominids. However, there is still a lack of consensus on the correspondence between muscle attachment sites and surface morphology of the proximal femoral diaphysis in chimpanzees. Two alternative observations have been proposed regarding the attachment site positions of gluteus maximus (GM) and vastus lateralis (VL) relative to two prominent surface features of the proximal femoral diaphysis, the lateral spiral pilaster and the inferolateral fossa. Here, we use a combination of virtual and physical dissection in an attempt to identify the exact correspondence between muscle attachment sites and osteological features in two specimens of Pan troglodytes verus. The results show that the insertion of the GM tendon is consistently inferolateral to the lateral spiral pilaster, and that a part of the inferolateral fossa consistently forms the attachment site of the VL muscular fibers. While overall musculoskeletal features are similar in the two specimens examined in this study, GM and VL exhibit different degrees of segregation at the level of the inferolateral fossa. One specimen exhibited tendinous GM fibers penetrating the posteromedial part of VL, with both GM and VL inserting at the inferolateral fossa. In the other specimen, GM and VL were separated by a lateral intermuscular septum, which inserted into the inferolateral fossa. Variation of proximal femoral muscle attachments in chimpanzees is thus greater than previously thought. Our results indicate that a conspicuous osteological feature such as the inferolateral fossa does not necessarily correspond to the attachment site of a single muscle, but could serve as a boundary region between two muscles. Caution is thus warranted when interpreting the surface topography of muscle attachment sites and inferring locomotor functions.
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