The Late Pleistocene Human species of Israel

Pour la première fois en Paléoanthropologie, des restes humains provenant de sites d’une même zone géographique peuvent permettre d’étudier l’influence de la variation (crânienne) pour discuter leur statut phylogénétique. Il s’agit des spécimens du Pléistocène supérieur découverts dans les sites moustériens d’Israël. L’interprétation taxonomique de ces vestiges est problématique. En effet, les raisons de cette variation sont toujours inconnues et les tentatives d’explication de ces différences morphométriques reflètent souvent les idées phylogénétiques des chercheurs aussi nettement que la nature des données. Aujourd’hui, cela se traduit par le penchant des paléoanthropologues à définir des espèces fossiles sur la base de différences anatomiques. Notre contribution teste l’hypothèse selon laquelle la variation observée entre les restes crâniens d’Amud, Qafzeh, Skhul et Tabun traduit bien des différences d’ordre spécifique. Nous allons essayer de rejeter l’hypothèse de l’absence de différence en proposant de nouvelles approches statistiques pour étudier cette problématique phylogénétique. Nous analysons la distribution de la courbe de régression d’une série de mesures communes à des paires de spécimens. Puis nous déterminons le STET (erreur standard de la courbe de régression) à partir de la modification d’une méthode proposée par Thackeray et al. (1997). Nous montrons que ce test (STET) permet de rejeter l’hypothèse lorsque l’on utilise des spécimens présentant de fortes différences taxonomiques mais ne le permet pas lorsque l’on ne considère que les fossiles israéliens.The human remains from the Late Pleistocene Mousterian sites in modern day Israel raised the issue of variation for the first time in the history of paleoanthropology. Their current interpretation is both problematic, in that the sources of their variation still remain unresolved, and historic, in that attempts at resolution reflect the currently accepted philosophy of the paleoanthropologists as strongly as they reflect the nature of the data. Today this philosophy can be seen in the penchant of some paleoanthropologists to define species taxa on the basis of consistent differences, no matter how minute. Here, we examine the question of whether the observed variation in the cranial remains from Amud, Qafzeh, Skhul, and Tabun reflects species differences. We try to refute a hypothesis of no difference, and suggest new approaches for examining this phylogenetic question. We report on the distribution of a testing statistic based on the standard error of the slope of regressions relating the measurements common to pairs of specimens. We show that this standard error test of the null hypothesis (STET) has the power to reject a null hypothesis for significant hominid taxonomic differences but does not reject the null hypothesis for the Israeli remains

What Did Our Ancestors Eat?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75025/1/j.1753-4887.1989.tb02765.x.pd

Palaeoanthropology - Sahelanthropus or 'Sahelpithecus'?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62951/1/419581a.pd

Tooth wear: the view of the anthropologist

Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental arches from tooth migration. Comparative studies of many different species have also documented these physiological processes supporting the idea of perpetual change over time. In particular, differential wear between enamel and dentine was considered a physiological process relating to the evolution of the form and function of teeth. Although evidence of attrition and abrasion has been known to exist among hunter-gatherer populations for many thousands of years, the prevalence of erosion in such early populations seems insignificant. In particular, non-carious cervical lesions to date have not been observed within these populations and therefore should be viewed as ‘modern-day’ pathology. Extrapolating this anthropological perspective to the clinical setting has merits, particularly in the prevention of pre-mature unnecessary treatment

Sixty Years of Modern Human Origins in the American Anthropological Association

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65197/1/aa.2003.105.1.89.pd

A comparison of sexual dimorphism and range of variation in Papio cynocephalus and Gorilla gorilla dentition

The dentitions of 48 baboons ( Papio cynocephalus ) and 242 gorillas ( Gorilla gorilla ) are compared metrically and the baboons are found to have a greater range of variation, and greater sexual dimorphism than the gorillas. This is explained in terms of the different ecologies of these species: life on the African savannah, with its sharp seasonal changes in available food, seems to have given selective advantage to broader niches than life in the rain forest. Further, the historic continuity of the savannah has provided fewer chances for allopatric speciation than the rain forest. These contrasts between forest and savannah speciation should provide insights into hominid evolution. In trying to judge whether australopithecines, probable savannah residents, can be lumped into one or several species, based upon dental variability, a comparison with baboons should be more informative than the now frequently used contrast with gorillas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41597/1/10329_2006_Article_BF02381794.pd

Hybridization in human evolution: Insights from other organisms

During the late Pleistocene, isolated lineages of hominins exchanged genes thus influencing genomic variation in humans in both the past and present. However, the dynamics of this genetic exchange and associated phenotypic consequences through time remain poorly understood. Gene exchange across divergent lineages can result in myriad outcomes arising from these dynamics and the environmental conditions under which it occurs. Here we draw from our collective research across various organisms, illustrating some of the ways in which gene exchange can structure genomic/phenotypic diversity within/among species. We present a range of examples relevant to questions about the evolution of hominins. These examples are not meant to be exhaustive, but rather illustrative of the diverse evolutionary causes/consequences of hybridization, highlighting potential drivers of human evolution in the context of hybridization including: influences on adaptive evolution, climate change, developmental systems, sex-differences in behavior, Haldane’s rule and the large X-effect, and transgressive phenotypic variation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151330/1/evan21787.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151330/2/evan21787_am.pd

High mutation rates explain low population genetic divergence at copy-number-variable loci in Homo sapiens

Copy-number-variable (CNV) loci differ from single nucleotide polymorphic (SNP) sites in size, mutation rate, and mechanisms of maintenance in natural populations. It is therefore hypothesized that population genetic divergence at CNV loci will differ from that found at SNP sites. Here, we test this hypothesis by analysing 856 CNV loci from the genomes of 1184 healthy individuals from 11 HapMap populations with a wide range of ancestry. The results show that population genetic divergence at the CNV loci is generally more than three times lower than at genome-wide SNP sites. Populations generally exhibit very small genetic divergence (G(st) = 0.05 ± 0.049). The smallest divergence is among African populations (G(st) = 0.0081 ± 0.0025), with increased divergence among non-African populations (G(st) = 0.0217 ± 0.0109) and then among African and non-African populations (G(st) = 0.0324 ± 0.0064). Genetic diversity is high in African populations (~0.13), low in Asian populations (~0.11), and intermediate in the remaining 11 populations. Few significant linkage disequilibria (LDs) occur between the genome-wide CNV loci. Patterns of gametic and zygotic LDs indicate the absence of epistasis among CNV loci. Mutation rate is about twice as large as the migration rate in the non-African populations, suggesting that the high mutation rates play dominant roles in producing the low population genetic divergence at CNV loci

The Stem Species of Our Species: A Place for the Archaic Human Cranium from Ceprano, Italy

One of the present challenges in the study of human evolution is to recognize the hominin taxon that was ancestral to Homo sapiens. Some researchers regard H. heidelbergensis as the stem species involved in the evolutionary divergence leading to the emergence of H. sapiens in Africa, and to the evolution of the Neandertals in Europe. Nevertheless, the diagnosis and hypodigm of H. heidelbergensis still remain to be clarified. Here we evaluate the morphology of the incomplete cranium (calvarium) known as Ceprano whose age has been recently revised to the mid of the Middle Pleistocene, so as to test whether this specimen may be included in H. heidelbergensis. The analyses were performed according to a phenetic routine including geometric morphometrics and the evaluation of diagnostic discrete traits. The results strongly support the uniqueness of H. heidelbergensis on a wide geographical horizon, including both Eurasia and Africa. In this framework, the Ceprano calvarium – with its peculiar combination of archaic and derived traits – may represent, better than other penecontemporaneous specimens, an appropriate ancestral stock of this species, preceding the appearance of regional autapomorphic features