卡氏尖在中国古人类化石中出现及其演化意义

欧洲与亚洲古人类之间的关系一直是人类演化研究的关注点。基于对化石形态的研究,一些学者认为中国与欧洲古人类之间在更新世中、晚期存在一定程度的基因交流,并提供了支持基因交流的系列形态证据,但古人类学界对其中一些形态特征的人群属性、功能意义及形成机制存在不同认识。本文采用釉质外表观察和CT扫描方法对卡氏尖在98枚中国古人类上颌臼齿化石的出现和表现情况进行了数据统计和分析,并与非洲和欧洲古人类进行了对比。本研究发现卡氏尖在中国古人类具有较高的出现率(27.6%-62.5%)和多种形态表现。此外,在多枚中国古人类上颌臼齿发现两个通常只出现在在黑猩猩和非洲早期人类的原始卡氏尖表现:齿带-原尖脊和齿冠舌侧横行沟及屋檐状结构。基于这些发现,作者支持卡氏尖是从猿类,经过不同演化阶段的古人类,一直延续到现代人的一个古老特征的观点。卡氏尖在中国古人类的表现特点提示出现在中国古人类的卡氏尖更有可能是古老原始特征的残余。本研究显示,卡氏尖在中国与欧洲古人类都具有较高出现率,而卡氏尖在中国古人类的表现程度较同时期欧洲古人类更为显著。因此目前还没有足够的可信证据支持卡氏尖是中国与欧洲古人类之间基因交流的造成化石形态特征。     

古人类对赭石的利用行为在其演化中的意义

长期以来赭石利用行为被视为人类行为现代性的标志之一,受到国内外考古学界的普遍关注。本文回溯和梳理了全球背景下赭石利用的起源、发展及其与人类演化史的关系。在现代人广泛分布于全球之后,赭石利用行为更加丰富和多样化地出现在各地,然而现有考古证据表明该行为并不是解剖学意义上的现代人突变性的发明。赭石利用不能被单纯地定义为现代人行为,而应是有着长久演化积累的现代性行为之一。在长期传播与演化过程中,赭石的功能从意识形态、艺术表达等逐渐扩展到作为矿物成分被用于实际生产生活。赭石的利用历史可追溯到中更新世中期,但其广泛分布仍与晚更新世以来现代人的广泛扩散直接相关,对于理解现代人的意识形态、社会组织方式以及艺术表达、精神文化发展都具有重要的意义。国内目前所发表的相关考古学证据相对较少,以下马碑遗址为代表的材料,也恰处于现代人在全球广泛扩散的窗口期,并伴有进步的细小石器镶嵌使用的证据,成为认识东亚现代人行为的关键性考古证据。     

科学家揭开中国古人类化石新成员——丹尼索瓦人的神秘面纱

我国是世界上发现古人类化石相当丰富的国家之一,迄今已在100余处地点发现了各种古人类化石,年代跨度在距今170万-1万年之间,这些古人类化石包括了直立人、早期智人和晚期智人. 在从20世纪80年代以来逐渐从西方开始流行起来的"走出非洲"这种人类演化故事的标准观点中,200多万年前直立人首先在非洲演化而出.之后大约在60...     

中更新世晚期中国古人类化石的形态多样性及其演化意义

近年对许家窑、许昌、华龙洞、澎湖、夏河、哈尔滨等人类化石开展的系统研究,引发了学界对中更新世晚期人类演化及分类的不同认识。基于对相关中国人类化石形态特征的分析,作者提出这一时期中国人类化石形态特征表现为四种类型：1）以中更新世晚期人类共有特征为主;2）以原始特征为主;3）以现代特征为主;4）独特形态组合。多数化石形态特征表现为前三种类型,而许昌和许家窑这种以硕大的头骨和巨大颅容量构成的独特形态组合在其他同时期化石还没有发现。化石形态的多样性提示,不同类型的中更新世晚期中国古人类对现代人的形成贡献不同。作者认为在该时期的人类化石形态多样性规律还未阐明的情况下,将具有混合或镶嵌特征的相关人类化石归入分类地位不确定的人群较为合适。     

中国古人类颅内模及脑演化研究进展

颅内模保存有脑表面的形态结构,是脑演化研究的直接证据。中国最早复原和研究的颅内模来自20世纪20年代北京周口店遗址发现的3号猿人头骨;此后虽然中国境内也相继发现了一些古人类的头骨化石,但由于古人类标本非常珍贵,不允许对其进行实体解剖,加上多数头骨破碎或者内部附有地层胶结物,导致颅内模无法成功复原。受技术水平及研究手段的限制,研究者一般只是侧重于化石外表形态结构的研究。高分辨率工业CT和3D软件的应用,可以在不损坏标本的情况下,虚拟复原出化石的内部解剖结构,使得一些重要的古人类化石标本的颅内模被复原出来,促进了脑演化的研究。近年来,本文第一作者采用新技术、新方法复原了南京直立人、柳江人等一些重要的中国古人类头骨的颅内模,通过对其颅容量、脑沟回特征、脑不对称性、脑表面的动、静脉血管压迹、各脑叶的大小、形状及比例的研究,获取了中国古人类脑形态特征变化的数据,为探讨东亚地区古人类的演化提供了参考信息。     

中国古人类遗址年代学的研究进展与问题

我国丰富的古人类遗存为研究东亚乃至全球古人类起源、迁徙和演化提供了重要的基础材料与数据。对已发表的2000多处旧石器时代古人类遗址年代学数据的整理和统计分析发现,绝大多数遗址目前仍缺少基本的年代学数据,不足20%的遗址开展过测年,仅10%左右具有相对可靠的年代学数据,只有极少数开展了多种测年方法的交叉定年。对于80多处出土古人类化石的遗址,亦过半存在明显的年代学争议。我们对一些古人类遗址中的常见各种复杂的同沉积和沉积后改造现象进行了详细分析,探讨了我国测年平台和测年队伍建设、考古发掘以及年代学采样与测年方法学等方面存在的问题,及其对遗址年代学研究的可能影响。基于此,笔者提出改善我国古人类年代学研究现状的可能措施,希望可以抛砖引玉,引发对该研究领域更多的关注和思考。     

早期现代人在中国的出现与演化

兴起于上世纪80年代的现代人起源研究与争论在近10年来呈现出一些新的趋势或特点, 主要体现在对现代人起源与演化细节过程的关注。这些新的关注点涉及早期现代人的出现与扩散、中更新世晚期-晚更新世早期人类化石特征变异及演化, 以及早期现代人出现与演化过程中的健康与生存适应活动三个方面。围绕这些问题, 中国古人类学界开展了相关研究并获得了一些新的发现和认识。本文对近10年来早期现代人在中国出现与演化领域的研究进行了回顾, 并对相关问题进行了讨论。     

更新世东亚人群连续演化的考古证据及相关问题论述

本文从考古文化的角度论证中国乃至东亚古人类演化的连续性。通过对石制品原料特点及开发利用方式、石器制作技术、石制品类型、形态与组合特点、区域文化传统演变等方面的分析,提出这里的旧石器时代文化一脉相承,古人群生生不息、连续演化。通过对中国旧石器文化体系中勒瓦娄哇技术制品、具有阿舍利风格的组合和石叶技术产品这些具有"西方元素"特点的文化成分的辨识与分析,指出更新世期间该地区石器生产基本维持在奥杜威模式内,来自西方的文化因素间或出现过,但从来没有成为主流,更没有发生对土著文化的置换,说明这一地区没有发生过大规模移民和人群更替事件;基因混合与文化交流可能发生过,但其过程是融合而非替代。秦岭诸遗址、北窑、大地湾、徐家城、乌兰木伦、织机洞、井水湾、黄龙洞等遗址的地层和测年数据表明东亚不存在距今10~4万年间的材料空白,人类演化的链条没有中断过。古气候和古生物信息也对末次冰期导致本土人群灭绝的论断提出否定。这些考古材料与信息对中国乃至东亚古人群连续演化及现代人类"连续进化附带杂交"的理论提供了强有力的论证和支持。"综合行为模式"等学说的提出强化了对本土人群生存能力的论述。对人类独特的行为特点与社会属性的观察和思考,也对本土人群与西方同类的隔离问题及不同地区人群长时期维持在同一物种内的可能性与动因提供了有益的启示。     

早、中更新世中国古人类年代序列与区域演化特征

我国早、中更新世古人类和旧石器遗址蕴含着丰富的早期人类活动和生存环境的背景信息,建立精确的遗址年代序列是分析古人类活动的基础。近二十年来,旧石器时代考古和测年研究为建立我国早期人类活动的年代框架提供了丰富的材料。本文分析了目前我国已发表的95个有独立测年数据的早、中更新世遗址,将其纳入黄土-古土壤年代框架,初步建立自200多万年至末次间冰期的古人类活动年代序列,根据它们的时空分布,进一步阐释了古人类在不同区域活动强度演变的时空特征。总体来看,这些遗址在泥河湾-周口店、秦岭山地、长江下游及长江流域以南(南方)四大区域呈现出聚集分布的特征;区域古人类活动强度主要表现在从早更新世的泥河湾-周口店、中更新世的秦岭山地、到中更新世晚期的长江中下游和南方区域的时空序列上。此外,仍有较多已发掘遗址缺少年代研究或存在测年问题,今后需要加强遗址的精确测年研究。     

Human cranial diversity and evidence for an ancient lineage of modern humans

This study examines the genetic affinities of various modern human groupings using a multivariate analysis of morphometric data. Phylogenetic relationships among these groupings are also explored using neighbor-joining analysis of the metric data. Results indicate that the terminal Pleistocene/early Holocene fossils from Australasia exhibit a close genetic affinity with early modern humans from the Levant. Furthermore, recent human populations and Upper Paleolithic Europeans share a most recent common ancestor not shared with either the early Australasians or the early Levantine humans. This pattern of genetic and phylogenetic relationships suggests that the early modern humans from the Levant either contributed directly to the ancestry of an early lineage of Australasians, or that they share a recent common ancestor with them. The principal findings of the study, therefore, lend support to the notion of an early dispersal from Africa by a more ancient lineage of modern human prior to 50 ka, perhaps as early as OIS 5 times (76-100 ka).     

现代人的出现与扩散——中国的化石证据

自2002年在周口店附近的田园洞发现大约4万年前的现代人化石以来,相继在湖北郧西黄龙洞、广西崇左智人洞等地点发现了早期现代人化石。这些化石发现证实大约10万年前早期现代人在华南地区已经出现。最近在湖南道县福岩洞发现的人类牙齿化石及相关研究进一步揭示具有完全现代形态的人类8万-12万年前在华南局部地区已经出现;而在这个时间段的华北地区,以许家窑人为代表的人类化石形态仍较原始,其演化尚未进入早期现代人阶段。这些研究发现提示,在中国地区,华南是现代人形成与扩散的中心区域,早期现代人以及完全现代类型的人类都可能首先在华南地区出现,然后向华北地区扩散。现有的化石形态证据显示,更新世晚期华南地区人类具有较大的演化变异,可能同时生存有几种不同的演化类群。智人洞属于从古老型智人向现代人演化的过渡类型,而道县则代表着演化进入完全现代类型的人类。基于前人研究及本文的分析,作者认为柳江、资阳、丽江、田园洞等更新世晚期人类化石特征比较进步,在演化上属于与道县相似的现代类型人类。值得注意的是,这些研究进展在引起对现代人在东亚地区出现和扩散关注的同时,古人类学界对其中涉及的许多问题还存在争论。本文在回顾分析这些研究进展的基础上,就相关问题进行了讨论。     

Energetics of reproduction and its evolutionary implications

The majority of invertebrates so far studied are more efficient converters of absorbed food energy to gametes than they are, as adults, to somatic tissues. Indeed, reproductive conversion efficiencies sometimes better the best conversion efficiencies associated with somatic production (usually in juveniles). Depending on species, this is achieved either by an increase in absorption relative to respiratory losses, or a reduction in respiratory losses relative to absorption, or by supplementing the energy absorbed from the food with that obtained from somatic stores and tissues, or by a combination of these. The fact that the metabolic processes associated with gamete production are distinct from those associated with the production of somatic tissues has implications for the theory of life-cycle evolution.     

The limits of adaptation: humans and the predator-prey arms race

In the history of life, species have adapted to their consumers by evolving a wide variety of defenses. By contrast, animal species harvested in the wild by humans have not adapted structurally. Nonhuman predators have high failure rates at one or more stages of an attack, indicating that victim species have spatial refuges or phenotypic defenses that permit further functional improvement. A new compilation confirms that species in the wild cannot achieve immunity from human predation with structural defenses. The only remaining options are to become undesirable or to live in or escape to places where harvesting by people is curtailed. Escalation between prey defenses and predators' weapons may be restricted under human dominance to interactions involving those low-level predators that have benefited from human overexploitation of top consumers.     

The stepwise development of the lamprey visual system and its evolutionary implications

Lampreys, which represent the oldest group of living vertebrates (cyclostomes), show unique eye development. The lamprey larva has only eyespot‐like immature eyes beneath a non‐transparent skin, whereas after metamorphosis, the adult has well‐developed image‐forming camera eyes. To establish a functional visual system, well‐organised visual centres as well as motor components (e.g. trunk muscles for locomotion) and interactions between them are needed. Here we review the available knowledge concerning the structure, function and development of the different parts of the lamprey visual system. The lamprey exhibits stepwise development of the visual system during its life cycle. In prolarvae and early larvae, the ‘primary’ retina does not have horizontal and amacrine cells, but does have photoreceptors, bipolar cells and ganglion cells. At this stage, the optic nerve projects mostly to the pretectum, where the dendrites of neurons in the nucleus of the medial longitudinal fasciculus (nMLF) appear to receive direct visual information and send motor outputs to the neck and trunk muscles. This simple neural circuit may generate negative phototaxis. Through the larval period, the lateral region of the retina grows again to form the ‘secondary’ retina and the topographic retinotectal projection of the optic nerve is formed, and at the same time, the extra‐ocular muscles progressively develop. During metamorphosis, horizontal and amacrine cells differentiate for the first time, and the optic tectum expands and becomes laminated. The adult lamprey then has a sophisticated visual system for image‐forming and visual decision‐making. In the adult lamprey, the thalamic pathway (retina–thalamus–cortex/pallium) also transmits visual stimuli. Because the primary, simple light‐detecting circuit in larval lamprey shares functional and developmental similarities with that of protochordates (amphioxus and tunicates), the visual development of the lamprey provides information regarding the evolutionary transition of the vertebrate visual system from the protochordate‐type to the vertebrate‐type.     

Patterns of humeral asymmetry among Late Pleistocene humans

Human humeral diaphyseal asymmetry in midshaft and mid-distal rigidity is assessed through the Late Pleistocene in samples of late archaic (Neandertal) and early modern humans. It is considered with respect to directionality (handedness), levels of asymmetry, body size and sexual differences. The overall Late Pleistocene sample indicates a right-handed preference in frequencies (right: 74.8%, left: 15.0%, ambiguous: 10.3%), which are similar to those of recent human samples. Average levels of humeral asymmetry are elevated relative to Holocene samples through all but the small Middle Paleolithic modern human and eastern Eurasian late Upper Paleolithic samples. Humeral asymmetry is especially high among the males relative to the females, and the possibility of a division of labor between uni-manual tasks (mostly male) and bi-manual tasks (mostly female) is considered. At the same time, there is a general pattern of increased asymmetry with larger body size, but it remains unclear to what extent it reflects body size versus sexual effects on bilateral humeral loading. There do not appear to have been substantial changes in humeral asymmetry through time, indicating a continuity of similar manual behavioral patterns through the Late Pleistocene, despite considerable changes in technology through the Late Pleistocene.     

Systematic and evolutionary implications of stamen position in Myrteae (Myrtaceae)

The taxonomy of Myrteae, the most species‐rich tribe of Myrtaceae, is notoriously difficult. Although the understanding of the phylogeny has improved, the morphological characteristics that support its cladistic configuration are still unknown. The present study evaluates stamen position and anthesis type as characters of systematic and evolutionary relevance. Sixty‐nine species from 41 genera across the tribe were checked using herbarium material and spirit collections. The results recognize three patterns of stamen position in the pre‐anthetic bud: straight, semi‐curved and strongly incurved. The three patterns of stamen position correspond to the phylogenetic structure of the tribe, supporting the topology of the clades. Incurving of stamens across the evolutionary history of Myrteae appears to be linked to hypanthium extension and leads to different anthesis types that may be related to shifts in pollination strategy. The accessibility of stamen position and its systematic consistency make this character a useful tool for field and herbarium identification, and allow the inference of relationships for taxa not yet sampled in molecular analyses. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 388–402.     

Stature estimation from complete long bones in the Middle Pleistocene humans from the Sima de los Huesos, Sierra de Atapuerca (Spain)

Systematic excavations at the site of the Sima de los Huesos (SH) in the Sierra de Atapuerca (Burgos, Spain) have allowed us to reconstruct 27 complete long bones of the human species Homo heidelbergensis. The SH sample is used here, together with a sample of 39 complete Homo neanderthalensis long bones and 17 complete early Homo sapiens (Skhul/Qafzeh) long bones, to compare the stature of these three different human species. Stature is estimated for each bone using race- and sex-independent regression formulae, yielding an average stature for each bone within each taxon. The mean length of each long bone from SH is significantly greater (p < 0.05) than the corresponding mean values in the Neandertal sample. The stature has been calculated for male and female specimens separately, averaging both means to calculate a general mean. This general mean stature for the entire sample of long bones is 163.6 cm for the SH hominins, 160.6 cm for Neandertals and 177.4 cm for early modern humans. Despite some overlap in the ranges of variation, all mean values in the SH sample (whether considering isolated bones, the upper or lower limb, males or females or more complete individuals) are larger than those of Neandertals. Given the strong relationship between long bone length and stature, we conclude that SH hominins represent a slightly taller population or species than the Neandertals. However, compared with living European Mediterranean populations, neither the Sima de los Huesos hominins nor the Neandertals should be considered ‘short’ people. In fact, the average stature within the genus Homo seems to have changed little over the course of the last two million years, since the appearance of Homo ergaster in East Africa. It is only with the emergence of H. sapiens, whose earliest representatives were ‘very tall’, that a significant increase in stature can be documented.     

晚更新世东北亚现代人迁移与交流范围的初步研究

民族考古学曾运用相似性概念对许多地区狩猎采集者的行为进行了研究,相关的民族考古学资料为研究旧石器时代晚期现代人的迁移性提供了可能。随着东北亚地区出土黑曜岩遗物遗址的增加,相应的黑曜岩产地分析研究也日益增多,目前有关长白山黑曜岩产地研究的资料已显著累积。本文参考了现今狩猎采集者的民族学资料,以产自长白山的黑曜岩遗物及分布于特定区域的有柄尖刃器为研究对象,发现晚更新世时期(MIS 2)东北亚现代人拥有广大的直接或间接活动范围。对现代人迁移性的研究不仅为区域石器制作技术的对比分析提供了便利,也为了解古人类的生存环境及适应策略提供了重要资料。