中国古人类牙齿尺寸演化特点及东亚直立人的系统地位

对中国境内不同时代人类牙齿测量数据的发析显示,中国古人类牙齿尺寸的总体演化趋势与世界其它地区人类一致,呈缩小变化,其中一个表现特点是中国直立人与早期智人在牙齿尺寸上不差别不大,但作者根据对中国古人类化石形态特征,生存年代等方面的综合分析认为中国直立人在化石形态,生存年代等方面均与智人有明显的不同,取消直立人,将其并入智人意见的证据还是不够充分的,目前仍宜将直立人与智人作为人属内两个不同的种来看待,     

南京2号人类头骨化石的复位和形态

南京2号人类头骨化石仅保留部分的额骨、顶骨、枕骨和颞骨,为一不完整的颅盖骨。其顶骨和枕骨有数条断裂缝,各断块之间有程度不一的错动,致使该颅盖骨显得外形异常。本项研究是对该颅盖骨的错动部分进行复位,结果表明,南京2号头骨有较大的顶骨、较小的上枕鳞相对宽度、可能较大的颅容量。这些形态提示该头骨与直立人有所不同而与早期智人相近。该头骨所具有的角圆枕、颞鳞顶缘形状、枕骨圆枕发育程度、枕骨的枕平面与项平面过渡情况、枕内隆突点与枕外隆突点的距离、头骨骨壁厚度、脑膜中动脉分支情况、头骨枕面观之轮廓线样式等形态细节,还很难作为可靠的依据把南京2号头骨鉴定为直立人。南京2号头骨很大可能是属于智人亚种(Homo sapiens sapiens)中的一员。     

现代人类的起源和迁移：来自母性遗传的证据

mtDNA具有极少发生重组、进化速度快等特点,能忠实反映群体的母性遗传,作为人类进化研究的一类重要工具,近年来取得了突出的成就,为现代人类的起源、迁移和进化提供了大量的证据。本文拟对这一领域的研究进展作一综述。Abstract:With special features,no recombination,fast speed of evolution etc.,mtDNA has been used to study origin,evolution and migration of Homo sapiens as a available genetic marker.The results of these researches provide remarkable evidence to human origin and evolution.This paper reviews the progress in these years.     

对人类进化全过程的思索

本文从人类的诞生,人类发展过程的连续与间断,人类进化过程中体质发展的不平衡性和现代人的进化等４方面来论述人类进化的全过程．     

中更新世非洲Bodo人类头骨化石与周口店直立人的比较--中国与非洲人类头骨特征对比之三

发现于埃塞俄比亚MiddleAwash地区Bodo地点距今60万年的人类头骨化石是迄今发现的最为古老和完整的非洲中更新世人类化石。由于Bodo头骨化石在形态特征上兼有直立人与智人的特点,多年来学术界对其分类地位一直存在争议。Rightmire认为Bodo头骨化石与BrokenHill及Petralona等在分类上属于古老型智人的中更新世人类更为接近,是非洲直立人向古老型智人过渡的代表。至少在距今60万年的中更新世早期直立人向古老型智人转变的成种事件在非洲就已经发生。以Bodo头骨为代表的一批更新世中期非洲和欧洲人类化石构成了可能是后期人类祖先的人属海德堡种。这些观点导致了近年学术界对古老型智人在非洲及欧亚出现时间以及更新世中期非洲和欧亚地区古人类相互之间演化关系的关注。基于这样的背景,本文对年代与Bodo化石接近的周口店直立人头骨特征与Bodo头骨的相似及差异表现情况进行了对比研究。结果发现Bodo头骨在一系列特征上与周口店直立人相似,同时在包括颅容量在内的其它一些特征上呈现出后期智人的特点,但总体形态上似乎与直立人更为相似。作者认为尽管这种进化上的镶嵌现象在中国古人类化石记录上也广泛存在,但由于中国人类化石标本在年代上的不确定性,目前还没有可靠的证据说明这种集直立人与智人化石特征为一体的镶嵌性在中国古人类化石出现的时间接近或早于非洲。考虑到中国与非洲直立人生存年代的巨大差异及人类演化的不同步或地区间差异,具有较多后期人类特征表现的人类首先出现在非洲是完全可能的。根据这些研究对比,作者就人类演化的镶嵌现象、更新世中期非洲与亚洲地区人类演化上的差异等问题进行了讨论。     

Human evolution — Where from here?

Thanks to language, mankind is rapidly developing into a eusocial1 animal, within a single world-wide structure. Biological evolution based on random genetic events is no longer a part of the future of the species, and cultural evolution has taken its place. Ease of communication between minds means that distinction between individuals is becoming irrelevant. Future progress in the single world-wide community to which mankind is rapidly developing will rather be a self-guided process — evolution by self-design.      

Hypermutability of genes in Homo sapiens due to the hosting of long mono-SSR

Simple sequence repeats (SSRs) are very common short repeatsin eukaryotic genomes. "Long" SSRs are considered "hypermutable"sequences because they exhibit a high rate of expansion andcontraction. Because they are potentially deleterious, longSSRs tend to be uncommon in coding sequences. However, severalgenes contain long SSRs in their exonic sequences. Here, weidentify 1,291 human genes that host a mononucleotide SSR longenough to be prone to expansion or contraction, being calledhypermutable hereafter. On the basis of Gene Ontology annotations,we show that only a restricted number of functions are overrepresentedamong those hypermutable genes including cell cycle and maintenanceof DNA integrity. Using a probabilistic model, we show thatgenes involved in these functions are expected to host longSSRs because they tend to be long and/or are biased in nucleotidecomposition. Finally, we show that for almost all functionswe observe fewer hypermutable sequences than expected undera neutral model. There are however interesting exceptions, forexample, genes involved in protein and RNA transport, as wellas meiosis and mismatch repair functions that have as many hypermutablegenes as expected under neutrality. Conversely, there are functions(e.g., collagen-related genes) where hypermutable genes aremore often avoided than in other functions. Our results showthat, even though several functions harbor unusually long SSRin their exons, long SSRs are deleterious sequences in almostall functions and are removed by purifying selection. The strengthof this purifying selection however greatly varies from functionto function. We discuss possible explanations for this intriguingresult.     

云南昭通发现的人类牙齿化石

在云南昭通过山洞发现的一枚人类左下第二臼齿化石,其形态和尺寸与智人类型的下臼齿最为接近;同时发现的哺乳动物化石有剑齿象、犀、獏等五种;时代可能为晚更新世。     

云南昭通发现的人类牙齿化石

在云南昭通过山洞发现的一枚人类左下第二臼齿化石,其形态和尺寸与智人类型的下臼齿最为接近;同时发现的哺乳动物化石有剑齿象、犀、獏等五种;时代可能为晚更新世。     

广东封开发现的人类牙齿化石

在广东封开峒中岩发现的一枚人类右上第二前臼齿化石,其形态与现代人特征基本一致;同时发现的哺乳动物化石有华南巨貘、中国犀等九种;时代为晚更新世。     

脑膜中动脉的形态变异及其在人类进化上的意义

对现代人、直立人、早期智人、晚期智人脑膜中动脉前支和后支压迹的形态的观察和对比发现：从直立人到现代人脑膜中动脉管径从粗到逐渐变细,分枝从简单到逐渐复杂,前支趋向于增大,后支趋向于缩小,呈现出一定的规律性,有地域性差异。作者认为脑膜中动脉的这种分布形式间接地反映了直立人向智人演化及现代人类形成过程中,大脑各部分比例的变化和功能的日益复杂对供血需求的影响。在研究颅骨与大脑之间的关系上及脑演化上,脑膜中动脉有一定的意义。     

Homo erectus: Ancestor or evolutionary side branch?

Controversies in paleoanthropology wax and wane, but substantial interest is currently focused on Homo erectus. This species has traditionally been regarded as a member in good standing of the human family, where it is placed as an evolutionary intermediate between earlier Homo habilis and later Homo sapiens. Recently, however, some workers have questioned whether the species exists at all. If its populations have been transformed slowly toward the modern condition, and if continuity with living people can be demonstrated in many geographic regions, then any separation of Homo erectus from Homo sapiens must be largely arbitrary. In that case, only one species should be recognized and this slowly changing lineage would have to be called Homo sapiens. Other paleontologists adopt a different view, arguing that Homo erectus is not only anatomically distinctive but also restricted in its geographic distribution. They claim that the fossils from Java and China are so specialized in appearance that they cannot lie in the mainstream of human evolution. Homo erectus, strictly defined as limited to the Far East, probably went extinct without issue. If so, more modern populations must have evolved from another source, perhaps one outside of Asia altogether.