Multivariate analysis of an early hominid metacarpal from swartkrans

Discriminant analysis permits hand bones of living primate genera to be represented as swarms of points in a multidimensional statistical framework within which intergroup relationships, and the affinities of fossil forms, can be examined. The metacarpal of Paranthropus from Swartkrans, South Africa, was so located with respect to groups of monkeys, apes, and modern man. The results suggest that the fossil metacarpal may be functionally similar to that of chimpanzees.     

Australopithecus garhi: a new species of early hominid from Ethiopia

The lack of an adequate hominid fossil record in eastern Africa between 2 and 3 million years ago (Ma) has hampered investigations of early hominid phylogeny. Discovery of 2.5 Ma hominid cranial and dental remains from the Hata beds of Ethiopia's Middle Awash allows recognition of a new species of Australopithecus. This species is descended from Australopithecus afarensis and is a candidate ancestor for early Homo. Contemporary postcranial remains feature a derived humanlike humeral/femoral ratio and an apelike upper arm-to-lower arm ratio.     

Archeological traces of early hominid activities, East of lake Rudolf, kenya

Excavations have demonstrated that stone artifacts occur stratified within beds of Lower Pleistocene (or end Pliocene) age. At one site a low-density scatter of worked stone objects occurs together with small but significant quantities of broken-up bones. Potassium-argon dates indicate an age greater than 2 million years; thus, this may be the oldest known hominid occupation site. More than 20 hominid fossils have been recovered from various sedimentary formations in the area.     

Late Miocene teeth from Middle Awash, Ethiopia, and early hominid dental evolution

Late Miocene fossil hominid teeth recovered from Ethiopia's Middle Awash are assigned to Ardipithecus kadabba. Their primitive morphology and wear pattern demonstrate that A. kadabba is distinct from Ardipithecus ramidus. These fossils suggest that the last common ancestor of apes and humans had a functionally honing canine-third premolar complex. Comparison with teeth of Sahelanthropus and Orrorin, the two other named late Miocene hominid genera, implies that these putative taxa are very similar to A. kadabba. It is therefore premature to posit extensive late Miocene hominid diversity on the basis of currently available samples.     

Molecular evidence for the early evolution of photosynthesis

The origin and evolution of photosynthesis have long remained enigmatic due to a lack of sequence information of photosynthesis genes across the entire photosynthetic domain. To probe early evolutionary history of photosynthesis, we obtained new sequence information of a number of photosynthesis genes from the green sulfur bacterium Chlorobium tepidum and the green nonsulfur bacterium Chloroflexus aurantiacus. A total of 31 open reading frames that encode enzymes involved in bacteriochlorophyll/porphyrin biosynthesis, carotenoid biosynthesis, and photosynthetic electron transfer were identified in about 100 kilobase pairs of genomic sequence. Phylogenetic analyses of multiple magnesium-tetrapyrrole biosynthesis genes using a combination of distance, maximum parsimony, and maximum likelihood methods indicate that heliobacteria are closest to the last common ancestor of all oxygenic photosynthetic lineages and that green sulfur bacteria and green nonsulfur bacteria are each other's closest relatives. Parsimony and distance analyses further identify purple bacteria as the earliest emerging photosynthetic lineage. These results challenge previous conclusions based on 16S ribosomal RNA and Hsp60/Hsp70 analyses that green nonsulfur bacteria or heliobacteria are the earliest phototrophs. The overall consensus of our phylogenetic analysis, that bacteriochlorophyll biosynthesis evolved before chlorophyll biosynthesis, also argues against the long-held Granick hypothesis.     

茂兰自然保护区的眼蝶资源及区系分析

2007年4月～2009年7月,我们对贵州茂兰国家级自然保护区的眼蝶科（Satyridae）进行采集,获得8属22种。其中,豹眼蝶属（Nosea）为茂兰新纪录属,三楔黛眼蝶（Lethe mekara）、重瞳黛眼蝶（L.trimacula）、蛇神黛眼蝶（L.satyrina）、豹眼蝶（Nosea hainanensis）、台湾矍眼蝶（Ypthima formosana）和魔女矍眼蝶（Y.medusa）共6种为茂兰新记录物种。矍眼蝶属和黛眼蝶属种类最多,为优势属。在世界动物地理区划中,茂兰保护区眼蝶以古北—东洋共有种和东洋区种为区系的优势成分;在中国地理区划中具有14个分布型。与国内其他自然保护区相比,茂兰保护区的眼蝶资源比较丰富,应该作为种质资源加以保护,并可适度开发和综合利用。     

贵州省象蜡蝉科昆虫名录及其区系分布

为象蜡蝉科农林果蔬害虫快速鉴定与防治提供依据,采用标本采集与资料整理相结合的方法,对贵州省象蜡蝉科昆虫名录及各种在中国动物地理区划中的区系分布进行研究。结果表明:贵州省象蜡蝉科昆虫共计7属15种。贵州省象蜡蝉东洋区性质显著;在中国地理区划水平上以华中区特有成分为主,华中区+华南区成分次之。     

阿勒泰地区硬蜱区系研究与分析

[目的]掌握阿勒泰地区硬蜱区系分布和群落结构.[方法]按照地理生态区划和不同生境类型选择阿勒泰地区6县1市7个生境类型32个调查位点进行蜱种类标本的采集和数量调查,采用群落生态学技术方法计算群落的丰富度、优势度、多样性和均匀性,研究其群落组成结构.[结果]阿勒泰地区共采获硬蜱4 544枚,隶属4属15种,其中地面游离蜱1 550枚,占总蜱数的34.11;;动物寄生蜱2 994枚,占65.89;.以草原革蜱(Dermacentor nuttalli Olenev,占34.64;)和银盾革蜱(Dermacentor niveus Neumann,占26.45;)为优势种群.[结论]阿勒泰地区蜱类物种丰富、分布区域广泛,但不同地理景观和生境类型的群落结构存在较大差异.     

A devonian spinneret: early evidence of spiders and silk use

A nearly complete spider spinneret was found in Middle Devonian rocks (about 385 to 380 million years old) near Gilboa, New York. This is the earliest evidence yet discovered for silk production from opisthosomal spigots, and therefore for spiders. Two previously known Devonian fossils described as spiders lack any apomorphies of the order Araneae and are probably not spiders. The spigots of the Devonian spinneret resemble those of members of the living suborder Mesothelae, but the number of spigots and their distribution are like those of members of the suborder Opisthothelae, infraorder Mygalomorphae. The Devonian spider belonged to a clade that may be the sister group of all other spiders, of Mesothelae, or of Opisthothelae.     

贵州真猎蝽亚科昆虫名录及区系分析

为完善贵州省猎蝽科昆虫的区系研究,记述了贵州省真猎蝽亚科昆虫29属52种,提供了各种在贵州省的详细分布.种级阶元区系分析结果表明:在世界动物地理区划水平上,东洋种47种,占90.4%;东洋古北共有种5种,占9.6 %.说明,贵州真猎蝽亚科昆虫的东洋区系性质显著.在中国动物地理区划水平上,贵州真猎蝽共有9个区系类型,其中...     

铁岭、南昌夜蛾科昆虫区系结构比较

本文从夜蛾科各工科在辽宁铁岭、江西南昌两地的种数及比重;夜蛾科昆虫区系类型及所占比重;两地夜蛾科昆虫在中国动物地理区划中的归属及所占比重以及两地与国内外几个地点的夜蛾科昆虫比较等四个方面来说明铁岭、南昌两地夜蛾科昆虫区系结构的异同。结果可以明显地看出:铁岭夜蛾科昆虫,绝大多数属于古北界种,所占比重几乎接近100％;而南昌则以东洋界种占较大优势,所占比重约72.9％。与国内几个地点比较,铁岭与黑龙江的共有种最多,占87.01％;而南昌同四川的共有种最多,占60.24％。与国外比较,铁岭、南昌两地均与日本共有种较多,分别占80.23％及78.71％。     

Molecular evidence for the early colonization of land by fungi and plants

The colonization of land by eukaryotes probably was facilitated by a partnership (symbiosis) between a photosynthesizing organism (phototroph) and a fungus. However, the time when colonization occurred remains speculative. The first fossil land plants and fungi appeared 480 to 460 million years ago (Ma), whereas molecular clock estimates suggest an earlier colonization of land, about 600 Ma. Our protein sequence analyses indicate that green algae and major lineages of fungi were present 1000 Ma and that land plants appeared by 700 Ma, possibly affecting Earth's atmosphere, climate, and evolution of animals in the Precambrian.     

甘肃省天祝藏族自治县蝶类多样性与区系分析

采用标本采集鉴定方法对甘肃省天祝藏族自治县内647个蝶类标本进行鉴定。结果表明,该区域中蝶类有绢蝶科(Pamassiidae)的1属4种,粉蝶科(Pieridae)的6属20种,眼蝶科(Satyridae)的12属16种,蛱蝶科(Nymohalidae)的10属12种,灰蝶科(Lycaenidae)的4属5种。蝶类区系组成分析表明,古北东洋界共有物种为13种,占总物种数的22.81%;古北界蝶类物种共44种,占总物种数的77.19%。     

黑里河国家级自然保护区蝶类资源调查及区系研究

分析研究黑里河国家级自然保护区蝶类区系,结果表明：黑里河国家级自然保护区蝴蝶共有7科54属88种;区系组成以古北区和东洋区共有种为主体,占总种数的54.54%。     

New fossil evidence on the sister-group of mammals and early mesozoic faunal distributions

Newly discovered remains of highly advanced mammal-like reptiles (Cynodontia: Tritheledontidae) from the Early Jurassic of Nova Scotia, Canada, have revealed that aspects of the characteristic mammalian occlusal pattern are primitive. Mammals and tritheledontids share an homologous pattern of occlusion that is not seen in other cynodonts. The new tritheledontids represent the first definite record of this family from North America. The extreme similarity of North American and African tritheledontids supports the hypothesis that the global distribution of terrestrial tetrapods was homogeneous in the Early Jurassic. This Early Jurassic cosmopolitanism represents the continuation of a trend toward increased global homogeneity among terrestrial tetrapod communities that began in the late Paleozoic.     

昆明市蝽科昆虫名录与区系分析

根据近年来采集标本、查看标本和查阅资料,对昆明市蝽科昆虫进行了统计和区系分析。结果表明,昆明市蝽科昆虫有44属70种(亚种),其中以菜蝽属种类最多,有4种;其次是岱蝽属、二星蝽属、曼蝽属、益蝽属和稻绿蝽属,各有3种(亚种)。蝽科昆虫东洋区特征极显著,仅在东洋区分布就有38种(亚种),占54.3%,但有较多古北区成分,东洋-古北区共有24种,占34.3%,并含有其他区系成分;在中国动物区系中,均在西南区有分布,但与华中区、华南区和青藏区共有成分较多,分别占74.3%、62.9%和47.1%,同时该区域特有成分较多,有9种,占12.9%,其他区也有一定分布。表明昆明市蝽科昆虫具有显著的东洋区特征和本区域特点。     

182W evidence for long-term preservation of early mantle differentiation products

Late accretion, early mantle differentiation, and core-mantle interaction are processes that could have created subtle (182)W isotopic heterogeneities within Earth's mantle. Tungsten isotopic data for Kostomuksha komatiites dated at 2.8 billion years ago show a well-resolved (182)W excess relative to modern terrestrial samples, whereas data for Komati komatiites dated at 3.5 billion years ago show no such excess. Combined (182)W, (186,187)Os, and (142,143)Nd isotopic data indicate that the mantle source of the Kostomuksha komatiites included material from a primordial reservoir that represents either a deep mantle region that underwent metal-silicate equilibration or a product of large-scale magmatic differentiation of the mantle. The preservation, until at least 2.8 billion years ago, of this reservoir-which likely formed within the first 30 million years of solar system history-indicates that the mantle may have never been well mixed.