scholarly journals Talar trochlear morphology may not be a good skeletal indicator of locomotor behavior in humans and great apes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuhei Nozaki ◽  
Motoharu Oishi ◽  
Naomichi Ogihara
Keyword(s):  
Geometric Morphometrics ◽  
Statistical Difference ◽  
Morphological Characteristics ◽  
Great Apes ◽  
Locomotor Behavior ◽  
Bipedal Locomotion ◽  
Apical Angle ◽  
Interspecific Differences ◽  
Fossil Hominins ◽  
Locomotor Behaviors

AbstractTo reconstruct locomotor behaviors of fossil hominins and understand the evolution of bipedal locomotion in the human lineage, it is important to clarify the functional morphology of the talar trochlea in humans and extant great apes. Therefore, the present study aimed to investigate the interspecific-differences of the talar trochlear morphology among humans, chimpanzees, gorillas, and orangutans by means of cone frustum approximation to calculate an apical angle and geometric morphometrics for detailed variability in the shape of the talar trochlea. The apical angles in gorillas and orangutans were significantly greater than those in humans and chimpanzees, but no statistical difference was observed between humans and chimpanzees, indicating that the apical angle did not necessarily correspond with the degree of arboreality in hominoids. The geometric morphometrics revealed clear interspecific differences in the trochlear morphology, but no clear association between the morphological characteristics of the trochlea and locomotor behavior was observed. The morphology of the trochlea may not be a distinct skeletal correlate of locomotor behavior, possibly because the morphology is determined not only by locomotor behavior, but also by other factors such as phylogeny and body size.

scholarly journals Characterizing the body morphology of the first metacarpal in the Homininae using 3D geometric morphometrics

2020 ◽  
Author(s):  
Jonathan Morley ◽  
Ana Bucchi ◽  
Carlos Lorenzo ◽  
Thomas A. Püschel
Keyword(s):  
Geometric Morphometrics ◽  
Precision Grip ◽  
Morphological Characteristics ◽  
Great Apes ◽  
Modern Human ◽  
The Body ◽  
Linear Discriminant ◽  
Homo Neanderthalensis ◽  
3D Geometric Morphometrics ◽  
Fossil Hominins

AbstractObjectivesExtinct hominins can provide key insights into the development of tool use, with the morphological characteristics of the thumb of particular interest due to its fundamental role in enhanced manipulation. This study quantifies the shape of the first metacarpal’s body in the extant Homininae and some fossil hominins to provide insights about the possible anatomical correlates of manipulative capabilities.Materials and methodsThe extant sample includes MC1s of modern humans (n=42), gorillas (n=27) and chimpanzees (n=30), whilst the fossil sample included Homo neanderthalensis, Homo naledi and Australopithecus sediba. 3D geometric morphometrics were used to characterize the overall shape of MC1’s body.ResultsHumans differ significantly from extant great apes when comparing overall shape. H. neanderthalensis mostly falls within the modern human range of variation although also showing a more robust morphology. H. naledi varies from modern human slightly, whereas A. sediba varies from humans to an even greater extent. When classified using a linear discriminant analysis, the three fossils are categorized within the Homo group.DiscussionThe results are in general agreement with previous studies on the morphology of the MC1. This study found that the modern human MC1 is characterized by a distinct suite of traits, not present to the same extent in the great apes, that are consistent with an ability to use forceful precision grip. This morphology was also found to align very closely with that of H. neanderthalensis. H. naledi shows a number of human-like adaptations consistent with an ability to employ enhanced manipulation, whilst A. sediba apparently presents a mix of both derived and more primitive traits.

scholarly journals Morphological differences in the calcaneus among extant great apes investigated by three-dimensional geometric morphometrics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuhei Nozaki ◽  
Hideki Amano ◽  
Motoharu Oishi ◽  
Naomichi Ogihara
Keyword(s):  
Geometric Morphometrics ◽  
Articular Surface ◽  
Three Dimensional ◽  
Great Apes ◽  
Functional Adaptation ◽  
Triceps Surae ◽  
Plantar Surface ◽  
Interspecific Differences ◽  
Morphological Differences ◽  
Calcaneal Tuberosity

AbstractInvestigating the morphological differences of the calcaneus in humans and great apes is crucial for reconstructing locomotor repertories of fossil hominins. However, morphological variations in the calcaneus of the great apes (chimpanzees, gorillas, and orangutans) have not been sufficiently studied. This study aims to clarify variations in calcaneal morphology among great apes based on three-dimensional geometric morphometrics. A total of 556 landmarks and semilandmarks were placed on the calcaneal surface to calculate the principal components of shape variations among specimens. Clear interspecific differences in calcaneal morphology were extracted, corresponding to the degree of arboreality of the three species. The most arboreal orangutans possessed comparatively more slender calcaneal tuberosity and deeper pivot region of the cuboid articular surface than chimpanzees and gorillas. However, the most terrestrial gorillas exhibited longer lever arm of the triceps surae muscle, larger peroneal trochlea, more concave plantar surface, more inverted calcaneal tuberosity, more everted cuboid articular surface, and more prominent plantar process than the orangutans and chimpanzees. These interspecific differences possibly reflect the functional adaptation of the calcaneus to locomotor behavior in great apes. Such information might be useful for inferring foot functions and reconstructing the locomotion of fossil hominoids and hominids.

scholarly journals Metabolic control of daily locomotor activity mediated by tachykinin in Drosophila

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sang Hyuk Lee ◽  
Eunjoo Cho ◽  
Sung-Eun Yoon ◽  
Youngjoon Kim ◽  
Eun Young Kim
Keyword(s):  
Locomotor Behavior ◽  
Sensory Inputs ◽  
Sucrose Diet ◽  
High Nutrient ◽  
Intracellular Ca ◽  
High Sucrose Diet ◽  
Locomotor Activities ◽  
Locomotor Behaviors ◽  
High Sucrose ◽  
Over Time

AbstractMetabolism influences locomotor behaviors, but the understanding of neural curcuit control for that is limited. Under standard light-dark cycles, Drosophila exhibits bimodal morning (M) and evening (E) locomotor activities that are controlled by clock neurons. Here, we showed that a high-nutrient diet progressively extended M activity but not E activity. Drosophila tachykinin (DTk) and Tachykinin-like receptor at 86C (TkR86C)-mediated signaling was required for the extension of M activity. DTk neurons were anatomically and functionally connected to the posterior dorsal neuron 1s (DN1ps) in the clock neuronal network. The activation of DTk neurons reduced intracellular Ca2+ levels in DN1ps suggesting an inhibitory connection. The contacts between DN1ps and DTk neurons increased gradually over time in flies fed a high-sucrose diet, consistent with the locomotor behavior. DN1ps have been implicated in integrating environmental sensory inputs (e.g., light and temperature) to control daily locomotor behavior. This study revealed that DN1ps also coordinated nutrient information through DTk signaling to shape daily locomotor behavior.

Limb proportions and positional behavior

2020 ◽  
pp. 321-334
Author(s):  
Adam D. Gordon ◽  
David J. Green ◽  
William L. Jungers ◽  
Brian G. Richmond
Keyword(s):  
Human Evolution ◽  
Pan Troglodytes ◽  
Body Shape ◽  
Great Apes ◽  
Positional Behavior ◽  
Prior Work ◽  
Australopithecus Africanus ◽  
Western Gorillas ◽  
Locomotor Behaviors ◽  
Limb Proportions

Major changes in body shape occurred during human evolution, but questions remain about body shape in australopiths. The present study investigates the specifics of the presumed relationships between limb indices and positional behavior underlying prior work that compared proportions among extant hominids in order to make inferences about extinct hominins. We find that although both intermembral index or ratio of diaphyseal and articular proportions distinguish humans from great apes, neigher correlates well with variation in the degree of arboreality in the locomotor repertoire of extant hominids. Brachial index and a ratio of diaphyseal and articular dimensions from the fore- and hindlimb, however, do correlate with degree of arboreality, and scale slightly positively allometrically within species in all extant taxa. These two observations are taken into consideration in a more nuanced interpretation of a reanalysis of articular-diaphyseal limb proportions in an expanded sample of the Sterkfontein postcrania. This study confirms previous findings that Australopithecus africanus had larger forelimb dimensions in relation to hindlimb dimensions than modern humans and A. afarensis, similar to the patterns seen in extant apes, particularly western gorillas. However, data presented here suggest that interpreting a particular taxon as “human-like” or “ape-like” may be overly simplistic. Instead, while both A. africanus and A. afarensis were almost certainly committed bipeds that incorporated some arboreality into their locomotor repertoire, A. africanus apparently used a set of locomotor behaviors that was more distinct from that of A. afarensis than Pan troglodytes and Gorilla gorilla are from each other.

scholarly journals Classification of Hallucal Sesamoid Bone Correlated with Hallux Valgus Severity

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lei Zhang ◽  
Junqiu Wang ◽  
Jiaju Liu ◽  
Jiangqin Luo
Keyword(s):  
Hallux Valgus ◽  
Statistical Difference ◽  
Three Dimensional ◽  
Morphological Characteristics ◽  
Metatarsophalangeal Joint ◽  
Metatarsal Head ◽  
Type I ◽  
Sesamoid Bone ◽  
First Metatarsophalangeal Joint

The hallucal sesamoid bones (HSBs), having an important role in reducing load per unit area on the first metatarsal head, can be injured commonly which also affected the first metatarsophalangeal joint and the surrounding structure. Meanwhile, differences among each HSB type may be a major factor affecting the occurrence and development of HV. So far, many researchers had learned that there are three different conditions in hallucal sesamoid bone affecting the choice of clinical surgery corresponding to different solutions in clinic. Thus, it is necessary to study the anatomical morphological characteristics of the HSB which can be helpful in clinical diagnosis and treatment, especially hallux valgus (HV). 150 X-ray and three-dimensional (3D) computed tomographic (CT) images consist of 72 left and 78 right metatarsals were applied in this anatomic study between two variables and showed by a simple scatter plot. The first metatarsophalangeal joint is divided into four different types: type I (no HSB, 1.3%), type II (with one HSB, 0.07%), type IIIa (with two HSBs when THB is bigger, 28%), type IIIb (with two HSBs when FHB is bigger, 65.3%), and type IV (with three HSBs, 4.7%). There was no statistical difference between the left and right sides, except HVA, Meary, and pitch (P<0.05); all a, b, c, d, and i have statistical difference between male and female (P<0.05). Meanwhile, HVA and IMA and HVA and type group have a significant correlation. In summary, HVA and IMA and HVA and classification of HSBs have significant correlations. The classification and location of HSBs can be an important basis to choose operation methods and postoperation evaluation.

scholarly journals From action to language: comparative perspectives on primate tool use, gesture and the evolution of human language

2012 ◽  
Vol 367 (1585) ◽  
pp. 4-9 ◽  
Author(s):  
James Steele ◽  
Pier Francesco Ferrari ◽  
Leonardo Fogassi
Keyword(s):  
Experimental Evidence ◽  
Tool Use ◽  
Close Association ◽  
Great Apes ◽  
Human Action ◽  
Human Language ◽  
Special Issue ◽  
Neural Representations ◽  
Language Representation ◽  
Fossil Hominins

The papers in this Special Issue examine tool use and manual gestures in primates as a window on the evolution of the human capacity for language. Neurophysiological research has supported the hypothesis of a close association between some aspects of human action organization and of language representation, in both phonology and semantics. Tool use provides an excellent experimental context to investigate analogies between action organization and linguistic syntax. Contributors report and contextualize experimental evidence from monkeys, great apes, humans and fossil hominins, and consider the nature and the extent of overlaps between the neural representations of tool use, manual gestures and linguistic processes.

Interspecific Differences in Weed Susceptibility to Steam Injury

2008 ◽  
Vol 22 (4) ◽  
pp. 719-723 ◽  
Author(s):  
Ramon G. Leon ◽  
Dylan T. Ferreira
Keyword(s):  
Weed Control ◽  
Production Systems ◽  
Morphological Characteristics ◽  
Grass Species ◽  
Content Type ◽  
Control Programs ◽  
Interspecific Differences ◽  
Wide Range ◽  
Common Purslane ◽  
Broadleaf Species

Thermal weed control methods have been incorporated into weed control programs in organic and conventional production systems. Flaming is commonly used, but steaming has been proposed to increase efficiency of heat transfer to weeds and reduce the risk of fire. The objective of this research was to measure injury to leaves of plant species that differ in leaf morphology and to measure injury to plants at different stages of plant development. The study was conducted in a glasshouse and plants were exposed to steaming at 400 C for 0.36 s—equivalent to a steaming speed of 2 km/h. Overall, leaf thickness was the best morphological characteristic to predict injury (r2 = 0.51), with greater thickness resulting in less injury. For broadleaf species only, species with wider leaves were injured more than species with narrower leaves (r2 = 0.64). Injury was greatest when plants had fewer than six true leaves and when their shoots were less than 10 cm long. There was a wide range of injury across species, and the grass species bermudagrass and perennial ryegrass were injured (68 to 81%) more than other species such as common purslane and English daisy (23 to 34%). Biomass of all species tested was reduced by approximately 40%, indicating that leaf injury was not the sole effect of steaming on plant growth. These results indicated that considering both visual estimates of injury and morphological characteristics is important to properly assess thermal weed control effectiveness.

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