Evolution of the supraorbital region in Upper Pleistocene fossil hominids from South-Central Europe

South-Central European fossil hominids dated to the Upper Pleistocene exhibit a distinct morphological and metric continuum in supraorbital form from early Neandertal (Krapina), through late Neandertals (Vindija), to early Upper Paleolithic hominids. The supraorbital morphologies pertinent to this continuum are documented, and the alterations in size and morphology are discussed ralative to the function of supraorbital superstructures and their relationship to overall craniofacial form. It is concluded that this continuum most likely reflects localized transition between Neandertals and modern man in this region of Europe.     

Dynamic bone remodeling in later Pleistocene fossil hominids

Histomorphometric analysis of femoral and tibial diaphyseal fragments from seven Late Archaic and three Early Modern humans are compared with those of the Pecos, a pre-Columbian Native American population. The ten samples, from Broken Hill (EM-793), Shanidar 2, 3, 4, 5, and 6, Tabun 1, and Skhul 3, 6, and 7, provide age-at-death results consistent with earlier estimates for most individuals. The Pleistocene groups exhibit less bone turnover and smaller osteons than Recent populations. Resorption and formation were both coupled and balanced in these Pleistocene populations, but the overall vigor of individual cells from both the osteoclast and osteoblast cell lines was less than in Recent populations. Thus the greater bone mass in Later Pleistocene members of the genus Homo is not the result of higher levels of bone turnover, at least among adults. © 1996 Wiley-Liss, Inc.     

Probit analysis of Upper Pleistocene hominids

Probit analysis allows the testing of the normality of a sample population where curve fitting and differential weighting occur simultaneously. Probit analysis may be utilized with small samples, and is ideal for use in the study of fossil populations. It is assumed that population which are normally distributed are likely to be in genetic equilibrium, so that graphic and computational probit analysis may be used to discern the effects of evolutionary forces on human populations. Probit analysis of cranial length in a sequence of Athenian population is presented in order to verify its sensitivity to these evolutionary forces. Probit analysis and other tests of homogeneity are applied to similar variables of Upper Pleistocene European Neandertal and modern man.Despite significant differences between variable means of Neandertal and modern man, probit analyses of their combined populations showed no less deviation from normality than either group separately. This suggests that the evolutionary changes in the cranium from the Neandertal stage to the modern stage of man were effected without significantly disrupting the genetic equilibrium of these populations, i.e. that rapid changes in these populations are unlikely to have occurred.     

Patterns of evolution in Middle Pleistocene hominids

This paper reviews the chronology and morphological variability of Middle Pleistocene H. erectus. specimens. Functional complexes are delineated within the skull and dentition, and their total morphological patterns quantified using univariate and multivariate statistical analysis. Statistical distances are calculated between H. erectus and other hominid samples for each complex, compared to illustrate patterns of mosaic evolution within the skull and dentition of middle Quaternary hominids, and estimated evolution rates are derived. An attempt is made to relate the observed morphological patterns to ecological shifts by early hominid communities, and to assess their significance for hominid taxonomy.     

Relative dental development of Upper Pleistocene hominids compared to human population variation

The relative development of permanent teeth in samples of Neandertal/archaic Homo and Early Modern/Upper Paleolithic hominids is compared to the range of variability found in three recent human samples. Both fossil hominid samples are advanced in relative M2 and M3 development compared to white French-Canadians, but only the Neandertal/archaic Homo M3 sample is advanced when compared to black southern Africans. Both fossil hominid samples are delayed in relative I1 and P3 development compared to the recent human samples. Two hypotheses concerning the significance of the advanced M3 and M2 development found in both hominid groups and southern Africans compared to French-Canadians are discussed. The first postulates that the differences in relative molar development are due simply to variation in tooth/jaw size relationships. The second postulates that the relatively advanced M3 and M2 development found in the fossil hominids and southern Africans is a correlate of their potential for advanced skeletal maturation compared to French-Canadians and other European-derived populations. It appears that dental development patterns have continued to evolve from the Upper Pleistocene to present times, and that Neandertals and Early Moderns shared similar patterns of relative dental development. © 1996 Wiley-Liss, Inc.     

The fossil fauna from an Upper Pleistocene site in Jordan

The fossil fauna from an Upper Pleistocene habitation site in Jordan is described. Seven species of mammal are represented, three of these being recorded for the fist time from Jordan. The faunal remains are compared with those from Mount Cannel and other Pleistocene sites in the Near East. It is suggested that the site was occupied during an early inter- stadial of the last glaciation when savannah conditions prevailed.     

A fossil hominid frontal from Velika Pećina (Croatia) and a consideration of Upper Pleistocene hominids from Yugoslavia

Fossil hominid remains dating to the Upper Pleistocene in Yugoslavia are reviewed. Particular emphasis is placed on the assessment of a hominid frontal from the site of Velika Pe?ina in northwestern Croatia. This specimen represents the earliest absolutely-dated hominid associated with the Upper Paleolithic in Europe. Also the hominid material from the site of Veternica is discussed, and data are presented on the new remains from ?andalja. It is concluded that no Neandertal remains, except for Krapina, have been found in Yugoslavia.     

The geological context of the Kanapoi fossil hominids

Recent study of the geological succession at Kanapoi reveals that there are at least three series of sediments younger than the early Pliocene Kanapoi sediments which repose unconformably on them. Both sets of terrace and placage deposits contain an admixture of reworked Pliocene fossils and younger fossils preserved at the time of deposition of the younger sediments. This discovery throws doubt on the homogeneous nature of the Kanapoi fossil hominid sample, and suggests instead thatAustralopithecus anamensis may consist of a chimera of an early Pliocene hominid with generally ape-like dentognathic and postcranial anatomy and considerably youngerHomo specimens with more human-like post-cranial bones.     

Senescence in European Middle Pleistocene hominids: The Atapuerca evidence

The mandibular specimens AT-250 and AT-793 (individual IV) and AT-888 (individual XXI) from the Atapuerca Middle Pleistocene sample show a combination of traits interpreted as evidence of senescence. In order to explore age-related mandibular changes relevant to the interpretation of the Atapuerca hominids, the sample of known age and sex from Spitalfields (London) and the Neolithic sample from Abu Hureyra (Syria) were used as a baseline. Results obtained indicate that the occurrence of an enlarged and posteriorly located mental foramen, in association with high alveolar resorption in AT-250 and AT-888, support the hypothesis of senescence in individuals IV and XXI from the Atapuerca sample. The findings suggest that European Middle Pleistocene populations lived long enough to reach senescence. The age at death for Middle Pleistocene hominids and Neanderthals has previously been estimated at around 40–45 years in the oldest specimens. The appearance of senescence processes before this age is indicative of higher rates of morphological aging in the clade which gave rise to Neanderthals. The anatomical significance of ageing features when considered in the context of craniofacial remodelling can help in the understanding of the taxonomic status of these morphological traits.     

The Omo-Turkana Basin fossil hominins and their contribution to our understanding of human evolution in Africa

The Omo-Turkana Basin, including the hominin fossil sites around Lake Turkana and the sites along the lower reaches of the Omo River, has made and continues to make an important contribution to improving our murky understanding of human evolution. This review highlights the various ways the Omo-Turkana Basin fossil record has contributed to, and continues to challenge, interpretations of human evolution. Despite many diagrams that look suspiciously like comprehensive hypotheses about human evolutionary history, any sensible paleoanthropologist knows that the early hominin fossil record is too meager to do anything other than offer very provisional statements about hominin taxonomy and phylogeny. If history tells us anything, it is that we still have much to learn about the hominin clade. Thus, we summarize the current state of knowledge of the hominin species represented at the Omo-Turkana Basin sites. We then focus on three specific topics for which the fossil evidence is especially relevant: the origin and nature of Paranthropus; the origin and nature of early Homo; and the ongoing debate about whether the pattern of human evolution is more consistent with speciation by cladogenesis, with greater taxonomic diversity or with speciation by anagenetic transformation, resulting in less taxonomic diversity and a more linear interpretation of human evolutionary history.     

Variation in enamel development of South African fossil hominids

Dental tissues provide important insights into aspects of hominid palaeobiology that are otherwise difficult to obtain from studies of the bony skeleton. Tooth enamel is formed by ameloblasts, which demonstrate daily secretory rhythms developing tissue-specific structures known as cross striations, and longer period markings called striae of Retzius. These enamel features were studied in the molars of two well known South African hominid species, Australopithecus africanus and Paranthropus robustus. Using newly developed portable confocal microscopy, we have obtained cross striation periodicities (number of cross striations between adjacent striae) for the largest sample of hominid teeth reported to date. These data indicate a mean periodicity of seven days in these small-bodied hominids. Important differences were observed in the inferred mechanisms of enamel development between these taxa. Ameloblasts maintain high rates of differentiation throughout cervical enamel development in P. robustus but not in A. africanus. In our sample, there were fewer lateral striae of Retzius in P. robustus than in A. africanus. In a molar of P. robustus, lateral enamel formed in a much shorter time than cuspal enamel, and the opposite was observed in two molars of A. africanus. In spite of the greater occlusal area and enamel thickness of the molars of both fossil species compared with modern humans, the total crown formation time of these three fossil molars was shorter than the corresponding tooth type in modern humans. Our results provide support for previous conclusions that molar crown formation time was short in Plio-Pleistocene hominids, and strongly suggest the presence of different mechanisms of amelogenesis, and thus tooth development, in these taxa.     

Population bottlenecks and Pleistocene human evolution

We review the anatomical and archaeological evidence for anearly population bottleneck in humans and bracket the time whenit could have occurred. We outline the subsequent demographicchanges that the archaeological evidence of range expansionsand contractions address, and we examine how inbreeding effectivepopulation size provides an alternative view of past populationsize change. This addresses the question of other, more recent,population size bottlenecks, and we review nonrecombining andrecombining genetic systems that may reflect them. We examinehow these genetic data constrain the possibility of significantpopulation size bottlenecks (i.e., of sufficiently small sizeand/or long duration to minimize genetic variation in autosomaland haploid systems) at several different critical times inhuman history. Different constraints appear in nonrecombiningand recombining systems, and among the autosomal loci most areincompatible with any Pleistocene population size expansions.Microsatellite data seem to show Pleistocene population sizeexpansions, but in aggregate they are difficult to interpretbecause different microsatellite studies do not show the sameexpansion. The archaeological data are only compatible witha few of these analyses, most prominently with data from Aluelements, and we use these facts to question whether the viewof the past from analysis of inbreeding effective populationsize is valid. Finally, we examine the issue of whether inbreedingeffective population size provides any reasonable measure ofthe actual past size of the human species. We contend that ifthe evidence of a population size bottleneck early in the evolutionof our lineage is accepted, most genetic data either lack theresolution to address subsequent changes in the human populationor do not meet the assumptions required to do so validly. Itis our conclusion that, at the moment, genetic data cannot disprovea simple model of exponential population growth following abottleneck 2 MYA at the origin of our lineage and extendingthrough the Pleistocene. Archaeological and paleontologicaldata indicate that this model is too oversimplified to be anaccurate reflection of detailed population history, and thereforewe find that genetic data lack the resolution to validly reflectmany details of Pleistocene human population change. However,there is one detail that these data are sufficient to address.Both genetic and anthropological data are incompatible withthe hypothesis of a recent population size bottleneck. Suchan event would be expected to leave a significant mark acrossnumerous genetic loci and observable anatomical traits, butwhile some subsets of data are compatible with a recent populationsize bottleneck, there is no consistently expressed effect thatcan be found across the range where it should appear, and thisabsence disproves the hypothesis.     

Allometric patterns of cranial bone thickness in fossil hominids

The interspecific allometry of five measures of total cranial bone thickness is examined in 10 extant catarrhine genera and two fossil hominid samples representing A. africanus and Asian H. erectus. Analysis of the modern sample shows that most interspecific variation in vault thickness can be accounted for by variation in body size. Correlation values are moderate to high (r = 0.75–0.98), and all variables exhibit positive allometry. The bone thickness:body mass relationship of modern humans broadly conforms with that of other primates. However, in the distribution of relative thickness throughout the skull, H. sapiens is distinguished by relative thickening of the parietal and extreme relative thinning of the temporal squama. The bone thickness:body mass relationship in the two early hominid species is examined using published mean body weight estimates generated from post-cranial predictor variables. A. africanus exhibits great similarity to modern humans in its relation to the catarrhine regression data and in the distribution of relative thickness throughout the skull. H. erectus also shows a modern human-like pattern in the distribution of its relative thickness; however, its bone thickness:body mass relationship is dissimilar to that displayed by all other taxa, including the other hominid species. On the basis of these results, it is suggested that the published body weight estimate assigned to H. erectus greatly underestimates actual mean body size for Asian members of this species. © 1996 Wiley-Liss, Inc.     

The dental developmental status of six East African juvenile fossil hominids

Radiographs of five juvenile fossil hominids from Koobi Fora, Kenya are described and presented together with measurements and observations made on the original speciments. Data are also presented for a single specimen from Olduvai Gorge, Tanzania. Four of these specimens are attributed to Paranthropus boisei (KNM ER 812, 1477 1820 and OH 30), and are all of remarkably similar dental developmental status. Conventional age estimates for these specimens of Paranthropus based on the first permanent molar, indicate an age at death of around 2·2 to 3 years. Perikymata counts on permanent lower central incisors of these specimens also indicate an age at death between 2·5 and 3 years. Two specimens attributed to early Homo (KNM ER 820 and 1507), are dentally more mature than specimens of Paranthropus boisei described here being closer to 5 years of age. Differences between the spacing and distribution of perikymata on the surfaces of incisor teeth are now apparent between Homo, Australopithecus. Paranthropus boisei and Paranthropus robustus: these are described in this paper. Details of the dental developmental patterns of these hominids are also discussed in the light of recent publications that have presented data about hominid eruption sequences and fossil hominid growth periods.     

Morphological variation in the nasal region of extant and fossil hominids

We describe here the mid-facial region of a skull of anatomically modern Homo sapiens (FAI 3/2/1) that exhibits upwardly divergent nasal bones. In previous literature, that pattern has been described as a diagnostic character state for the robust early hominid taxon Paranthropus. This specimen supports our viewpoint that nasal region morphology varies extensively within and between living hominoid primate taxa, in patterns that provide a basis for understanding how microevolutionary variation serves as the basis for macroevolutionary transformations.     

Regional variation in tooth size and pathology in fossil hominids.

Tooth size and dental pathology in fossil hominids were studied to test for regional differences in these parameters. The results showed little regional variation in tooth size for the Middle and Upper Pleistocene sites compared (except for Krapina) but considerable differences in the severity of attrition and dental pathology. These differences were considered indicative of regional differences in the functional load borne by the teeth, and in view of the similar technological status of the groups studied, were attributed to environmental differences in the diet. Since, in all regions, reduction in tooth size appeared to continue at the same rate for the periods investigated, no association can be established between presumed selective pressures related to differences in functional demands made on the dentition, and tooth reduction.     

The place of Tam Hang in Southeast Asian human evolution

In February 1934, Jacques Fromaget of the Geological Service of Indochina discovered the Tam Hang rockshelter during prospecting work in Northern Laos. During his excavations, the geologist discovered seventeen anatomically modern human skulls. Ten of these skulls have been recovered in association with six largely-complete skeletons. These fossils, which are dated by ¹⁴C to 15.7 ka, are used to address issues related to anatomical variation and migration in Southeast Asia during the Late Pleistocene. Excellent preservation of the skeletal material allows for estimation of body size and shape in a sample of young adults. Cranial metrics are also used to assess affiliations between Tam Hang and other Southeast Asian fossil samples in an effort to address questions about population migration. This fossil sample demonstrates that Late Pleistocene human activity may be productively addressed by continued work in the highlands of mainland Southeast Asia.