Locomotion, posture, and the foramen magnum in primates: Reliability of indices and insights into hominin bipedalism

The position (FMP) and orientation (FMO) of the foramen magnum have been used as proxies for locomotion and posture in extant and extinct primates. Several indices have been designed to quantify FMP and FMO but their application has led to conflicting results. Here, we test six widely used indices and two approaches (univariate and multivariate) for their capability to discriminate between postural and locomotor types in extant primates and fossil hominins. We then look at the locomotion of australopithecines and Homo on the base of these new findings. The following measurements are used: the opisthocranion–prosthion (OP–PR) and the opisthocranion–glabella (OP–GL) indices, the basion–biporion (BA–BP) and basion–bicarotid chords, the foramen magnum angle (FMA), and the basion–sphenoccipital ratio. After exploring the indices variability using principal component analysis, pairwise comparisons are performed to test for the association between each index and the locomotor and postural habits. Cranial size and phylogeny are taken into account. Our analysis indicates that none of the indices or approaches provides complete discrimination across locomotor and postural categories, although some differences are highlighted. FMA and BA–BP distinguish respectively obligate and facultative bipeds from all other groups. For what concerns posture, orthogrades and pronogrades differ with respects to OP–PR, OP–GL, and FMA. Although the multivariate approach seems to have some discrimination power, the results are most likely driven by facial and neurocranial variability embedded in some of the indices. These results demonstrate that indices relying on the anteroposterior positioning of the foramen may not be appropriate proxies for locomotion among primates. The assumptions about locomotor and postural habits in fossil hominins based on foramen magnum indices should be revised in light of these new findings

Whole Brain Size and General Mental Ability: A Review

We review the literature on the relation between whole brain size and general mental ability (GMA) both within and between species. Among humans, in 28 samples using brain imaging techniques, the mean brain size/GMA correlation is 0.40 (N = 1,389; p < 10−10); in 59 samples using external head size measures it is 0.20 (N = 63,405; p < 10−10). In 6 samples using the method of correlated vectors to distill g, the general factor of mental ability, the mean r is 0.63. We also describe the brain size/GMA correlations with age, socioeconomic position, sex, and ancestral population groups, which also provide information about brain–behavior relationships. Finally, we examine brain size and mental ability from an evolutionary and behavior genetic perspective

New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day ‘modern’ morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens1 or evolved gradually over the last 400 thousand years2. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315?±?34 thousand years (as determined by thermoluminescence dating)3, this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent

Man as a Member of Society: Part III of the Series Science and Faith

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Laboratoire d'anthropologie

Mathias-Duval , Topinard Paul, Chudzinski Théophile, Manouvrier , Mahoudeau P.-G. Laboratoire d'anthropologie. In: Rapport sur l'École pratique des hautes études, 1888-1889. 1888. pp. 127-133

Laboratoire d'anthropologie

Mathias-Duval , Topinard Paul, Chudzinski Théophile, Manouvrier , Mahoudeau P.-G. Laboratoire d'anthropologie. In: Rapport sur l'École pratique des hautes études, 1887-1888. 1887. pp. 135-140

Laboratoire d'anthropologie

Mathias-Duval , Topinard Paul, Chudzinski Théophile, Manouvrier , Mahoudeau P.-G. Laboratoire d'anthropologie. In: Rapport sur l'École pratique des hautes études, 1888-1889. 1888. pp. 127-133