19 research outputs found

    Relationships between the hard and soft dimensions of the nose in Pan troglodytes and Homo sapiens reveal the positions of the nasal tips of Plio-Pleistocene hominids

    Full text link
    By identifying homogeneity in bone and soft tissue covariation patterns in living hominids, it is possible to produce facial approximation methods with interspecies compatibility. These methods may be useful for producing facial approximations of fossil hominids that are more realistic than currently possible. In this study, we conducted an interspecific comparison of the nasomaxillary region in chimpanzees and modern humans with the aim of producing a method for predicting the positions of the nasal tips of Plio-Pleistocene hominids. We addressed this aim by first collecting and performing regression analyses of linear and angular measurements of nasal cavity length and inclination in modern humans (Homo sapiens; n = 72) and chimpanzees (Pan troglodytes; n = 19), and then performing a set of out-of-group tests. The first test was performed on four subjects that belonged to the same genus as the training sample, i.e., Homo (n = 2) and Pan (n = 2), and the second test, which functioned as an interspecies compatibility test, was performed on Pan paniscus (n = 1), Gorilla gorilla (n = 3), Pongo pygmaeus (n = 1), Pongo abelli (n = 1), Symphalangus syndactylus (n = 3), and Papio hamadryas (n = 3). We identified statistically significant correlations in both humans and chimpanzees with slopes that displayed homogeneity of covariation. Prediction formulae combining these data were found to be compatible with humans and chimpanzees as well as all other African great apes, i.e., bonobos and gorillas. The main conclusion that can be drawn from this study is that our set of regression models for approximating the position of the nasal tip are homogenous among humans and African apes, and can thus be reasonably extended to ancestors leading to these clades

    Non-Standard Errors

    Get PDF
    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Towards the restoration of ancient hominid craniofacial anatomy: Chimpanzee morphology reveals covariation between craniometrics and facial soft tissue thickness

    Get PDF
    In modern humans, facial soft tissue thicknesses have been shown to covary with craniometric dimensions. However, to date it has not been confirmed whether these relationships are shared with non-human apes. In this study, we analyze these relationships in chimpanzees (Pan troglodytes) with the aim of producing regression models for approximating facial soft tissue thicknesses in Plio-Pleistocene hominids. Using CT scans of 19 subjects, 637 soft tissue, and 349 craniometric measurements, statistically significant multiple regression models were established for 26 points on the face and head. Examination of regression model validity resulted in minimal differences between observed and predicted soft tissue thickness values. Assessment of interspecies compatibility using a bonobo (Pan paniscus) and modern human subject resulted in minimal differences for the bonobo but large differences for the modern human. These results clearly show that (1) soft tissue thicknesses covary with craniometric dimensions in P. troglodytes, (2) confirms that such covariation is uniformly present in both extant Homo and Pan species, and (3) suggests that chimp-derived regression models have interspecies compatibility with hominids who have similar craniometric dimensions to P. troglodytes. As the craniometric dimensions of early hominids, such as South African australopithecines, are more similar to P. troglodytes than those of H. sapiens, chimpanzee-derived regression models may be used for approximating their craniofacial anatomy. It is hoped that the results of the present study and the reference dataset for facial soft tissue thicknesses of chimpanzees it provides will encourage further research into this topic

    Visual Depictions of Our Evolutionary Past: A Broad Case Study Concerning the Need for Quantitative Methods of Soft Tissue Reconstruction and Art-Science Collaborations

    Get PDF
    Flip through scientific textbooks illustrating ideas about human evolution or visit any number of museums of natural history and you will notice an abundance of reconstructions attempting to depict the appearance of ancient hominins. Spend some time comparing reconstructions of the same specimen and notice an obvious fact: hominin reconstructions vary in appearance considerably. In this review, we summarize existing methods of reconstruction to analyze this variability. It is argued that variability between hominin reconstructions is likely the result of unreliable reconstruction methods and misinterpretation of available evidence. We also discuss the risk of disseminating erroneous ideas about human evolution through the use of unscientific reconstructions in museums and publications. The role an artist plays is also analyzed and criticized given how the aforementioned reconstructions have become readily accepted to line the halls of even the most trusted institutions. In conclusion, improved reconstruction methods hold promise for the prediction of hominin soft tissues, as well as for disseminating current scientific understandings of human evolution in the future

    Towards the restoration of ancient hominid craniofacial anatomy: Chimpanzee morphology reveals covariation between craniometrics and facial soft tissue thickness.

    No full text
    In modern humans, facial soft tissue thicknesses have been shown to covary with craniometric dimensions. However, to date it has not been confirmed whether these relationships are shared with non-human apes. In this study, we analyze these relationships in chimpanzees (Pan troglodytes) with the aim of producing regression models for approximating facial soft tissue thicknesses in Plio-Pleistocene hominids. Using CT scans of 19 subjects, 637 soft tissue, and 349 craniometric measurements, statistically significant multiple regression models were established for 26 points on the face and head. Examination of regression model validity resulted in minimal differences between observed and predicted soft tissue thickness values. Assessment of interspecies compatibility using a bonobo (Pan paniscus) and modern human subject resulted in minimal differences for the bonobo but large differences for the modern human. These results clearly show that (1) soft tissue thicknesses covary with craniometric dimensions in P. troglodytes, (2) confirms that such covariation is uniformly present in both extant Homo and Pan species, and (3) suggests that chimp-derived regression models have interspecies compatibility with hominids who have similar craniometric dimensions to P. troglodytes. As the craniometric dimensions of early hominids, such as South African australopithecines, are more similar to P. troglodytes than those of H. sapiens, chimpanzee-derived regression models may be used for approximating their craniofacial anatomy. It is hoped that the results of the present study and the reference dataset for facial soft tissue thicknesses of chimpanzees it provides will encourage further research into this topic

    El conde de Floridablanca y su época

    No full text
    El 30 de diciembre de 1808 moría José Moñino Redondo, conde de Floridablanca, titular que fue de la primera Secretaría de Estado de la monarquía hispánica (1777-1792) y, a la sazón, presidente de la Junta Central Suprema. Su actividad política se desarrolló durante los años considerados como de plenitud del reformismo ilustrado en España en los que procuró desplegar un programa de modernización del país que lo pusiera en sintonía con la Europa del momento. Su caída en desgracia y su posterior recuperación para la política hacen de él un personaje enormemente atractivo, aunque su trayectoria ofrece aún espacios velados. Los artículos que conforman este dossier aportan nuevos datos, reflexión e interpretación con el ánimo de contribuir a una mejor caracterización del político que, sin duda, marcó con su gestión un período clave de la historia de España. Le 30 décembre 1808 décédait José Moñino Redondo, comte de Floridablanca, ancien membre du premier Secrétariat d'État de la monarchie hispanique (1777-1792) et à sa mort, président de la Junta Central Suprema. Son activité politique a coïncidé avec les années de plénitude du réformisme éclairé en Espagne qui virent se développer un programme de modernisation destiné à élever le pays au niveau de l'Europe du moment. Sa chute en disgrâce et son retour en politique font de lui un personnage très attrayant, même si sa trajectoire comprend encore nombre d'inconnues. Les articles qui composent ce dossier apportent de nouveaux faits, une réflexion et une interprétation inédites qui permettent de mieux cerner l'homme politique qui, sans aucun doute, marqua par sa gestion une période clé de l'histoire de l'Espagne
    corecore