Cranial capacity evolution in Homo erectus and early Homo sapiens.

This paper investigates patterns of cranial capacity evolution in Homo erectus, early Homo sapiens, and in regional subsamples of H. erectus. Specifically, models explaining evolution of cranial capacity in these taxa are evaluated with statistical techniques developed for the analysis of time series data. Regression estimates of rates of evolution in cranial capacity are also obtained. A non-parametric test for trend suggests that cranial capacity in both H. erectus and early H. sapiens may increase significantly through time. Cranial capacity in an Asian subsample of H. erectus (comprised of Chinese and Indonesian specimens) increases significantly through time. Other subsamples of H. erectus (African, Chinese, and Indonesian) do not appear to increase significantly through time. Regression results generally corroborate results of the test for trend. Spatial and temporal variation may characterize evolution of cranial capacity in H. erectus. Different patterns of cranial capacity evolution may distinguish H. erectus from early H. sapiens.     

南京直立人的高耸鼻梁和气候适应

为论证南京直立人高耸的鼻梁是对气候的适应,本文检验了有关鼻骨的3种测量项目;结果表明:鼻尖指数和鼻根指数用来表达整个骨性鼻梁的外突程度是有价值的,但眶间宽高指数不能用来说明整个鼻梁外突程度。Carey和Steegmann氏著作中的各人群鼻尖指数和鼻根指数数据和相应的气候资料表明,干燥地区人群的鼻比潮湿地区的要较外突,寒冷地区人群的鼻要比温暖地区的较外突。这种鼻的外突程度与干、寒气候的关系可以从人鼻的解剖学和呼吸生理学方面得到支持。因纽特人(爱斯基摩人)虽然鼻梁并未达到高耸级别,但有因上颌窦缩小而明显扩大的鼻腔,大的鼻甲、鼻道等。因此,因纽特人的鼻形态代表鼻对寒冷气候适应的另一种方式,不能用作证据来否认鼻梁高耸与气候之间的关系。另外,对南京直立人化石地点的孢子花粉、植硅体的研究表明,南京直立人是生活在冰期环境中,当时的冰期在很大程度上可以与冰期盛期或大冰期相对比。综上所述,南京直立人鼻梁高耸是对寒冷气候适应的结果,未必是由于基因交流的结果;这是对南京直立人鼻梁高耸的成因的目前一个最合理的解释。     

Hominid taphonomy: Transport of human skeletal parts in an artificial fluviatile environment

Flume experiments demonstrate that human skeletal parts sort into lag and transportable groups in a current flow of 31 cm/sec. Orientations, rates and types of movement, and stable positions are recorded. Density of a skeletal part is correlated with the average rate of movement, whereas wet weight in air, weight in water, and volume are not. Shape is an important but unquantifiable factor. Complete crania are the fastest moving elements; individual cranial fragments are in the lag group. Omo fluviatile deposits show a preponderance of hominid lag elements, whereas Olduvai and East Rudolf perilacustrine deposits present a mixture of transportable and lag elements.     

Mapping and taphonomic analysis of the Homo erectus loci at Locality 1 Zhoukoudian, China

From a detailed analysis of published and unpublished sources, we constructed a digitized three-dimensional, stratigraphically-controlled excavation grid of Zhoukoudian Locality 1 in order to assess the spatial relationships of the excavated materials. All 15 fossil Homo erectus loci were mapped on the grid. Meter cubes were used in excavation starting in 1934, and Loci H through O, established between 1934 and 1937, were mapped to within 1 m(3)vertical and horizontal provenience. Loci A through G, established between 1921 and 1933, were excavated in the northernmost part of Locality 1 by unmapped quarrying, but their stratigraphic levels were recorded. We could localize Loci A through G on the grid system by utilizing locations of remaining walls, stratigraphic sections, excavation reports, excavation maps, and photographs. Loci contained skeletal elements of Homo erectus individuals scattered over areas of the cave floor of up to 9 m in diameter. Scoring of taphonomic damage on the Homo erectus sample, as observed on casts and originals, demonstrates that 67% of the hominid sample shows bite marks or other modifications ascribed to large mammalian carnivores, particularly the large Pleistocene cave hyena, Pachycrocuta brevirostris. Virtually all of the remaining Homo erectus skeletal assemblage shows breakage consistent with this taphonomic pattern of fragmentation. Bioturbation by digging carnivores is the most likely explanation for a fragment of Homo erectus Skull XI discovered 1 m below its other conjoined portions in Locus L. Carbon on all the Homo erectus fossils from Locus G, a circumscribed area of 1-meter diameter, earlier taken to indicate burning, cooking, and cannibalism, is here interpreted as detrital carbon deposited under water, perhaps the result of hyaenid caching behavior. Locus G records the close stratigraphic and horizontal association of stone artifacts with Homo erectus and other vertebrate skeletal elements, an association that is seen at other loci as well. Layer 4 of the excavation contains equid cranial bone previously interpreted to have been burned while fresh. We here document that Locus B Homo erectus, including Skull I, is stratigraphically associated with this evidence, but at some 10-12 m distance. Even though the presence of wood-stoked fires and hearths is not supported by geochemical results, evidence of fire at Locality 1 in the form of burned bone is confirmed. Contextual relationships of fossil skeletal elements, relationships of carnivore damage and stone tool cutmarks on bone, and evidence of the burning of fresh bone associated with Homo erectus and stone tools support a model of transient hominid scavenging aided by the use of fire at the large hyenid den that became Zhoukoudian Locality 1. Although the original excavation catalogue from Locality 1, as well as a significant number of fossils and stone artifacts, were lost during World War II, catalogue numbers on the many surviving specimens can be used to locate fossils and artifacts within the three-dimensional grid provided in this paper.     

再论南京直立人的高耸鼻梁和气候适应

对南京直立人所具有的高耸鼻梁, 本文作者曾从人鼻的功能、鼻梁高耸程度与气候因素的关系以及因纽特人的鼻对寒冷气候的适应等方面进行过论证,认为是对气候适应的结果。本文从南京直立人的生存年代、若干形态项目的可靠性、人类的适应性以及高耸鼻梁的化石人类谱系对这一问题作进一步的论证。结果表明: 1)尚无可靠的证据能够否定南京直立人是生活在距今58—62万年这一年代测定数据。在南京直立人生存时,欧洲远古人类尚未具有像南京直立人那样的高耸鼻梁; 2)人类高耸鼻梁这一适应性特征的形成会有永久性的影响, 是遗传特征, 其后代即使生活在与其祖先不同的气候环境里, 这个特征也不会马上改变; 3)如果有所谓的Bodo高鼻梁的化石人类谱系存在的话, 则南京直立人的高耸鼻梁与欧洲化石人类的基因或与这个Bodo谱系的基因并无遗传上的关系。一个合理的解释是, 南京直立人的高耸鼻梁不可能意味着西方血统。     

Cranial base morphology and temporal bone pneumatization in Asian Homo erectus

The external morphological features of the temporal bone are used frequently to determine taxonomic affinities of fossils of the genus Homo. Temporal bone pneumatization has been widely studied in great apes and in early hominids. However, this feature is rarely examined in the later hominids, particularly in Asian Homo erectus. We provide a comparative morphological and quantitative analysis of Asian Homo erectus from the sites of Ngandong, Sambungmacan, and Zhoukoudian, and of Neandertals and anatomically modern Homo sapiens in order to discuss causes and modalities of temporal bone pneumatization during hominid evolution. The evolution of temporal bone pneumatization in the genus Homo is more complex than previously described. Indeed, the Zhoukoudian fossils have a unique pattern of temporal bone pneumatization, whereas Ngandong and Sambungmacan fossils, as well as the Neandertals, more closely resemble the modern human pattern. Moreover, these Chinese fossils are characterized by a wide midvault and a relatively narrow occipital bone. Our results support the point of view that cell development does not play an active role in determining cranial base morphology. Instead, pneumatization is related to available space and to temporal bone morphology, and its development is related to correlated morphology and the relative disposition of the bones and cerebral lobes. Because variation in pneumatization is extensive within the same species, the phyletic implications of pneumatization are limited in the taxa considered here.     

周口店直立人3号头骨的性别和年龄:南京直立人头骨的启示

周口店直立人3号头骨是1929年发现的, 被步达生鉴定为一青春期或成年期的女性个体的头骨。后来, 步达生改变了观点, 认为该头骨是代表青春期早期的男性个体。魏敦瑞同意步达生的意见, 但认为该头骨应属于8岁或9岁的男性个体。此后,周口店直立人3号头骨的性别和年龄的鉴定一直困扰着许多古人类学家。1993年发现的南京直立人成年女性头骨在形态上和尺寸上与周口店直立人3号头骨有相近之处。本文对周口店直立人3号头骨与南京直立人等头骨作了形态和测量上的比较, 结果表明: 从头骨的尺寸大小, 眶上圆枕、枕圆枕和肌嵴的发育程度以及头骨骨壁厚度等来看, 周口店3号头骨有理由被认为是女性个体的。该头骨的鼓骨裂、下颌骨关节窝、泪腺窝、额窦、骨缝等都无法证明其是幼年个体。周口店直立人3号头骨应代表成年女性个体。     

Particulate versus integrated evolution of the upper body in late pleistocene humans: A test of two models

Evolutionary biologists are largely polarized in their approaches to integrating microevolutionary and macroevolutionary processes. Neo-Darwinians typically seek to identify population-level selective and genetic processes that culminate in macroevolutionary events. Epigeneticists and structuralists, on the other hand, emphasize developmental constraints on the action of natural selection, and highlight the role of epigenetic shifts in producing evolutionary change in morphology. Accordingly, the ways in which these paradigms view and address morphological contrasts between classes of related organisms differ. These paradigms, although seldomly explicitly stated, emerge in paleoanthropology as well. Considerations of postcranial morphological contrasts between archaic and modern humans typically fall into one of two broad interpretive models. The first derives from the neo-Darwinian perspective and holds that evolution in the postcranial skeleton was largely mosaic (operating in a particulate manner), and that temporal change in specific traits informs us about behavioral shifts or genetic evolution affecting isolated anatomical regions (i.e., adaptive behavioral inferences can be made from comparative studies of individual trait complexes). The alternative model follows from the epigeneticist paradigm and sees change in specific postcranial traits as correlated responses to change in overall body form (involving shifts in regulation of skeletal growth, or selective and developmental responses to broad adaptive shifts). By this view, integration of functional systems both constrains and directs evolution of various traits, and morphological contrasts inform us about overall change in body form related to change in such things as overall growth patterns, climatic adaptation, and technological dependency. These models were tested by confirmatory factor analysis using measures of upper body form and upper limb morphological traits in Eurasian Neandertal and early modern fossils and recent human samples. Results indicate (1) a model of morphological integration fits the data better than a model of no integration, but (2) this integration accounts for less than half of the variance in upper limb traits, suggesting a high degree of tolerance for particulate evolution in the context of an integrated upper body plan. Significant relationships were detected between joint shapes and body size, between humeral shaft shape and body size and chest shape, and between measures of biomechanical efficiency and robusticity. The observed morphological differences between late archaic and early modern humans reflect particulate evolution in the context of constraints imposed by genetic and morphological integration. While particulate approaches to interpreting the fossil record appear to be justified, attention must also be paid to delineating the nature and extent of morphological integration and its role in both constraining and producing observed patterns of variation between groups. Confirmatory factor analysis provides a means of examining trait covariance matrices, and serves as a useful method of identifying patterns of integration in morphology. © 1996 Wiley-Liss, Inc.     

周口店北京猿人研究

简要地介绍了北京猿人化石产地、头部和四肢形态与现代人不同之处、行为、生存的年代和环境以及在人类演化中的位置。     

Homo erectus brain sizes by subspecies

Homo erectus fossils can be divided into four zoogeographic zones that show different rates of endocranial expansion during the Pleistocene. When these are also grouped into three time levels, we find small increases from early to middle forms, and regularly greater increases from middle to late forms. These increases fit a regular pattern that also accomodates all archaic types, including Neandertals, as late subspecies ofH. erectus.     

A re-evaluation of the metric diversity within Homo erectus

Previous work by several researchers has suggested that the cranial sample from Zhoukoudian possesses a unique metric pattern relative to the African and Asian specimens assigned to Homo erectus. The current study readdresses this issue with an expanded fossil sample and a larger and more comprehensive set of cranial measurements. To test the patterns present in the assemblage, canonical variates analysis was performed using a covariance matrix generated from the Howells data set. From this, interindividual Mahalanobis distances were computed for the fossils. Random expectation statistics were then used to measure statistical significance of the Mahalanobis distances. The results show that the Zhoukoudian hominids exhibit a unique metric pattern not shared by the African and Indonesian crania sampled. In these tests the Hexian calvaria resembled the African and Indonesian specimens and differed significantly from the craniometric pattern seen in the Zhoukoudian fossils. The Zhoukoudian specimens are characterized by a wide midvault and relatively narrow occipital and frontal bones, while the African and Indonesian crania (including Hexian) have relatively broad frontal and occipital dimensions compared to their midvaults. These results do not suggest that a multiple-species scenario is necessary to encompass the variation present in the sample. Based on the current evidence it is more probable that this variation reflects polytypism influenced by environmental adaptation and/or genetic drift.     

A Homo habilis maxilla and other newly-discovered hominid fossils from Olduvai Gorge, Tanzania

In 1995, a 1.8 million year old hominid maxilla with complete dentition (OH 65) was excavated from Bed I in the western part of Olduvai Gorge. The molar crowns are small relative to the long flaring roots, and the root of the canine is very long and straight. The broad maxilla with wide U-shaped palate and the form of the tooth roots closely match those of KNM-ER 1470 which, in its parietal size and morphology, matches the type specimen of Homo habilis, OH 7. Thus, OH 65 and KNM-ER 1470 group with OH 7 as representatives of H. habilis while some other Olduvai specimens, such as OH 13 and OH 24, have more in common in terms of morphology and brain size with Australopithecus africanus. Between 1995 and 2007, the OLAPP team has recovered teeth of eight other hominid individuals from various parts of Olduvai Gorge. These have been identified as belonging to H. habilis, Paranthropus boisei, and Australopithecus cf. africanus.     

The Indonesian Homo erectus brain endocasts revisited

New brain endocast reconstructions of Homo erectus discoveries from Indonesia since 1963 (H. erectus VI, 1963; VII, 1965; VIII, 1969) have been made and their volumes determined. In addition, older discoveries (H. erectus I, 1891; II, 1937; IV, 1937–38) have been reendocast and reconstructed, and have yielded volumes considerably different from those previously published. This is particularly so in the case of Dubois's original discovery, which yields a volume of 940 ml rather than the widely quoted volume of 750 ml. In addition, a number of morphological observations regarding hemispheric asymmetries (petalias) are provided, which suggest a condition similar to modern Homo sapiens.     

中国直立人形态特征的变异——颅骨测量数据的统计分析

近年,亚洲直立人化石特征的变异及其意义引起了学术界较多的关注。不断有学者提出周口店直立人无论在非测量性特征,还是在测量特征方面都具有不同于印度尼西亚及非洲直立人的表现特点,有人甚至对将周口店直立人化石特征作为直立人的典型特征的观点提出了置疑。为进一步探讨这些有争议的问题,本文采用多变量统计分析方法对33件非洲和欧亚地区直立人颅骨测量数据进行了分析。我们发现亚洲大陆的周口店和南京直立人与生活在东南亚群岛的印度尼西亚直立人具有不同的颅骨测量特征。中国标本以较窄的前额部和枕部,以及宽阔的颅骨中部为特点。而印度尼西亚标本的额部和枕部的宽度与颅骨中部的宽度相对较为接近。非洲直立人在这些颅骨测量特征的表现上与印度尼西亚直立人接近,呈现出相对宽阔的额部和枕部。中国的和县直立人在颅骨测量特征的表现上与印度尼西亚和非洲直立人接近,而与周口店和南京直立人明显不同。基于这些发现,本文就直立人头骨测量特征的稳定性、周口店直立人颅骨特征的表现特点、东亚直立人的地区变异与时代变化、头骨形态与测量特征的对应性等问题进行了讨论。     

Cranial morphology of Javanese Homo erectus: new evidence for continuous evolution, specialization, and terminal extinction

Our current knowledge of the evolution of Homo during the early to middle Pleistocene is far from complete. This is not only because of the small number of fossil samples available, but also due to the scarcity of standardized datasets which are reliable in terms of landmark identification, interobserver error, and other distorting factors. This study aims to accurately describe the cranial morphological changes of H. erectus in Java using a standardized set of measurements taken by the authors from 18 adult crania from Sangiran, Trinil, Sambungmacan, and Ngandong. The identification of some obscure landmarks was aided by the use of micro-CT imaging. While recent studies tend to emphasize evolutionary conservatism in Javanese H. erectus, our results reinforce the theory that chronologically later groups experienced distinct morphological changes in a number of cranial traits. Some of these changes, particularly those related to brain size expansion, are similar to those observed for the genus Homo as a whole, whereas others are apparently unique specializations restricted to Javanese H. erectus. Such morphological specializations in Java include previously undescribed anteroposterior lengthening of the midcranial base and an anterior shift of the posterior temporal muscle, which might have influenced the morphology of the angular torus and supramastoid sulcus. Analyses of morphological variation indicate that the three crania from Sambungmacan variously fill the morphological gap between the chronologically earlier (Bapang-AG, Bapang Formation above the Grenzbank zone in Sangiran) and later (Ngandong) morphotypes of Java. At least one of the Bapang-AG crania, Sangiran 17, also exhibits a few characteristics which potentially indicate evolution toward the Ngandong condition. These strongly suggest the continuous, gradual morphological evolution of Javanese H. erectus from the Bapang-AG to Ngandong periods. The development of some unique features in later Javanese H. erectus supports the hypothesis that this Javanese lineage went extinct without making significant contributions to the ancestry of modern humans.     

La Ferrassie 6 and the development of Neandertal pubic morphology

Functional interpretations of the mediolateral elongation and superoinferior flattening of the superior pubic ramus of Neandertals require knowledge of its ontogeny. Metric comparisons between the La Ferrassie 6 Neandertal infant, aged 3-5 years, and a sample of modern infants reveal that the acetabulosymphyseal length of La Ferrassie 6, relative to femoral length and iliac breadth, falls at the limits of the range of variation of the modern infants, while the relative height of its superior pubic ramus is indistinguishable from that of the modern sample. It appears that acetabulosymphyseal elongation of the Neandertal pubis is a feature which is expressed quite early in ontogeny, well before puberty. Superoinferior flattening and ventral margin thinning of the superior ramus probably appear later in Neandertal ontogeny.