水洞沟第12地点古人类用火研究

水洞沟遗址第12地点在2007年的考古发掘中从距今约1.1万年前的灰烬层中出土大量破碎的石块。对这些石块的形态观察、大小统计和岩性分析表明它们是被人类选择、加热、利用而后破碎的。用同类石料所做的模拟实验表明, 这些石块是在经历高温热烧后被浸入水中崩解破碎的, 即它们是生活在遗址的先民用来烧水和烹煮液体食物的"烧石"。对遗址区地下水和地表水所做的水质检测分析显示, 该地的生水中大肠杆菌含量严重超标, 不能被直接食(饮)用,但煮沸后此项危害得以消除; 生态环境资料表明当地晚更新世末以来生长着多种可被人类食用的植物, 其中的一些可食性籽粒必须经过烹煮方可被享用。该地点的烧石是首次被确认和论证的旧石器时代先民复杂、间接用火的考古证据, 对探讨该遗址古人群对特定环境的适应生存方略与聪明才智, 以及古人类用火能力与方式的发展演化, 具有重要的学术意义。     

Phylogeography of the bushmaster (Lachesis tnuta: Viperidae): implications for neotropical biogeography, systematics, and conservation

We used mitochondrial gene sequences to reconstruct phylogenetic relationships among subspecies of the bushmaster, Lachesis muta. These large vipers are widely distributed in lowland tropical forests in Central and South America, where three of four allopatric subspecies are separated by montane barriers. Our phylogeny indicates that the four subspecies belong to two clades, the Central American and South American lineages. We use published molecular studies of other taxa to estimate a 'reptilian mtDNA rate' and thus temporal boundaries for major lineage divergences in Lachesis. We estimate that the Central and South American forms diverged 18-6 Mya, perhaps due to the uplifting of the Andes, whereas the two Central American subspecies may have diverged 11-4 Mya with the uprising of the Cordillera de Talamanca that separates them today. South American bushmasters from the Amazon Basin and the Atlantic Forest are not strongly differentiated, perhaps due to episodic gene flow during the Pleistocene, when suitable habitat for this species was at times more continuous. Our results agree with previous evidence that genetic divergence among some neotropical vertebrates pre-dated Pleistocene forest fragmentation cycles and the appearance of the Panamanian Isthmus. Based on morphological, behavioral, and molecular evidence, we recognize three species of Lachesis. In addition to L. muta, the widespread South American form, the Central American forms are treated as distinct species (L. meknocephak and L. stenophrys), each deserving of special conservation status due to restricted distribution and habitat destruction.     

Assay for polyunsaturated fatty acids by argentation-thin-layer chromatography using commercial thin-layer plates

A simple, rapid, and convenient procedure for silver nitrate impregnation of commercial precoated silica gel plates is described. Silica-gel plates (Silica gel 60, E. Merck) were sprayed with 40% silver nitrate in water, dried in air, and activated at 100°C for 30 min. Samples containing fatty acid methyl esters were applied as 0.5- to 1.0-cm streaks and developed with a solvent system of benzene:ethyl acetate (9:1, v/v). The plates were sprayed with 70% sulfuric acid saturated with potassium dichromate, and the spots were detected by careful heating at 120°C for 90 min. This procedure is useful for separation and isolation of various species of fatty acid methyl esters and for simple, rapid, and reproducible estimation of microgram quantities of materials by spectrodensitometry of the chromatogram.     

Population genetic structure of a rare high-elevation black fly, Metacnephia coloradensis, occupying Colorado lake outlet streams

1. Using a portion of the mitochondrial cytochrome oxidase I gene, we evaluated the population genetic structure of a geographically rare black fly (Metacnephia coloradensis) that is a habitat specialist in outlet streams of large, productive, alpine lakes in Colorado, U.S.A. Given its rarity and life history traits that restrict dispersal, we hypothesised that genetic structure would show a signature of allopatric fragmentation associated with climatic warming since Pleistocene glaciations. 2. We tested for genetic isolation by distance (IBD) and applied nested clade analysis (NCA) to ask whether current genetic structure is primarily a consequence of historic fragmentation or if there is evidence of ongoing gene flow. 3. Only four populations were located despite a thorough search of potential sites, and they demonstrated a significant degree of genetic structure (F_ST = 0.17). However, there was some evidence of IBD in a plot of genetic versus geographic distance, and NCA further supported IBD and restricted ongoing gene flow in clades at all nested levels. Compared with a more widespread alpine black fly (Prosimulium neomacropyga) in the same region, M. coloradensis demonstrated significantly less population genetic structure. 4. Although these results counterintuitively implicate limited ongoing gene flow driving current population structure, significant IBD may be a signature of historic gene flow, especially if migration–drift equilibrium has not yet been reached since a late‐Pleistocene fragmentation event. Extraordinarily dense local populations probably allowed M. coloradensis to maintain large effective population sizes and minimise genetic drift rates. 5. Despite large local populations, M. coloradensis is vulnerable to continued rapid environmental change because of its limited geographic distribution and high habitat specificity.     

田阳百峰遗址发现的含手斧石制品研究

百峰遗址位于百色盆地西部右江南岸的第四级河流阶地。本文报道我们在该遗址调查时采集的37件石制品,其中包括2件手斧和16件手镐。这些手斧和手镐均用扁平砾石为毛坯加工而成,暗示生活在百色盆地的早期人类加工石器时利用附近可获得的原料。在遗址的网纹红土地层中,新暴露出来的石制品和玻璃陨石处于同一层位,显示百色盆地第四级阶地的石制品制作时代与玻璃陨石的降落事件时间一致,在中更新世早期。     

Design, chemical synthesis, and expression of genes for the three human color vision pigments.

Color vision in humans is mediated by three pigments from retinal cone photoreceptor cells: blue, green, and red. We have designed and chemically synthesized genes for each of these three pigments. The genes were expressed in COS cells, reconstituted with 11-cis-retinal chromophore, and purified to homogeneity using an immunoaffinity procedure. To facilitate the immunoaffinity purification, each pigment was modified at the carboxy terminus to contain an additional eight amino acid epitope for a monoclonal antibody previously used to purify bovine rhodopsin. The spectra for the isolated pigments had maxima of 424, 530, and 560 nm, respectively, for the blue, green, and red pigments. These maxima are in excellent agreement with the maxima previously observed by microspectrophotometry of individual human cone cells. The spectra are the first to be obtained from isolated human color vision pigments. They confirm the original identification of the three color vision genes, which was based on genetic evidence [Nathans, J., Thomas, D., & Hogness, D.S. (1986) Science 232, 193].     

Récentes découvertes de restes d'Hominidés fossiles en Chine du Sud

After the discovery of the controversial hominids and artefacts at the Longgupo site, three Early Pleistocene sites in the southern valleys of the Changjiang (Yangtze) were excavated from 1998 to 2000 in order to test the hypothesis that the hominids exist in China before 2 Ma. Three cheek teeth of Meganthropus palaeojavanicus, more than six hundreds pieces of artefacts of Mode 1 technology and thousands pieces of mammal fossils of Villafranchian age were unearthed in situ at the Longgudong Site in Hubei Province. More than 120 pieces of artefacts of Mode 1 technology and seven thousands pieces of mammal fossils of Villafranchian age were unearthed in situ at the Renzidong Site in Anhui Province. Although no new materials of hominids and artefacts were unearthed at the Yuanmou Man Site at Danawu in Yunnan Province, new materials of mammalian fauna confirm the horizon yielding the Yuanmou Man fossils is of the Early Pleistocene. These new discoveries imply that the appearance of hominids in China is very likely before 2 Ma. If the new report of 3 Ma artefact from Yuxian of the Nihewan Basin in northern China can be confirmed, it will be a strong support for the Continuity Theory.     

尉家小堡遗址石制品的初步研究

山西北部桑干河中游的尉家小堡遗址,是华北地区以细石器加工技术为特征的旧石器时代晚期遗址,石制品岩性以硅质岩和火山角砾岩为主。细石核全部为楔形石核,显示出一套较为成熟而稳定的制坯及剥片工艺,包括软锤修整楔状缘、压制产生细石叶等。石器类型全部为刮削器。5.6%的拼合率说明此处为原地埋藏遗址。通过与同时代桑干河流域的其他遗址石制品的比较和遗址出土较精致的穿孔骨制品的现象判断,此遗址的年代应在旧石器时代晚期之末。     

Eye pigments of the blood-sucking insect, Triatoma infestans Klug (Hemiptera, Reduviidae).

The pigmentation of black (wild) and red (mutant) eyes of Triatoma infestans was studied spectrophotometrically and compared with red-eyed (wild) and white-eyed (mutant) forms of Drosophila melanogaster. The spectral absorption profiles of the black and red eye pigments of T. infestans were similar to each other and to that of the wild-type eyes of D. melanogaster. The similarity to the wild form of D. melanogaster indicated that both eye forms of T. infestans contained ommochromes of the xanthommatin type, a finding confirmed by ascending paper chromatography. Pteridines, melanins, and ommins were not detected as eye pigments in T. infestans. The eye color difference in T. infestans was assumed to be a function of the xanthommatin concentration, with a smaller content of ommochrome in red eyes, although this probably did not affect the insect's visual acuity. These data support other findings regarding the similarities between black- and red-eyed specimens of T. infestans for other characteristics.     

泥河湾盆地上沙嘴石制品

泥河湾盆地上沙嘴出土石制品34件,包括石核、石片、石器和断块,并伴随纳玛象头骨与马和犀等的牙齿化石。上沙嘴石制品最初发现于1972年,报道后在国内外引起强烈反响。1980年该地点的时代被修改为晚更新世。近年来的考察再次表明,上沙嘴地点就位于下更新统泥河湾组,且得到了古地磁测年为距今160~170万年的确认。     

Bacterioferritin: properties, structural and functional organization of the dps gene regulatary region

The paper considers the properties of bacterioferritin Dps, which is involved in the sequestering of iron ions, forms the ferrihydrite core inside the protein cavity, and functions as a major nucleoid protein. Experimental evidence on the effect of microwave irradiation on the dps gene expression is presented. The structural and functional organization of its regulatory region is analyzed, and the technological prospects of bacterioferritin application for designing new materials with desired properties are discussed.     

High levels of population subdivision in a morphologically conserved Mediterranean toad (Alytes cisternasii) result from recent,multiple refugia: evidence from mtDNA,microsatellites and nuclear genealogies

Pleistocene glaciations often resulted in differentiation of taxa in southern European peninsulas, producing the high levels of endemism characteristic of these regions (e.g. the Iberian Peninsula). Despite their small ranges, endemic species often exhibit high levels of intraspecific differentiation as a result of a complex evolutionary history dominated by successive cycles of fragmentation, expansion and subsequent admixture of populations. Most evidence so far has come from the study of species with an Atlantic distribution in northwestern Iberia, and taxa restricted to Mediterranean‐type habitats remain poorly studied. The Iberian Midwife toad (Alytes cisternasii) is a morphologically conserved species endemic to southwestern and central Iberia and a typical inhabitant of Mediterranean habitats. Applying highly variable genetic markers from both mitochondrial and nuclear genomes to samples collected across the species’ range, we found evidence of high population subdivision within A. cisternasii. Mitochondrial haplotypes and microsatellites show geographically concordant patterns of genetic diversity, suggesting population fragmentation into several refugia during Pleistocene glaciations followed by subsequent events of geographical and demographic expansions with secondary contact. In addition, the absence of variation at the nuclear β‐fibint7 and Ppp3caint4 gene fragments suggests that populations of A. cisternasii have been recurrently affected by episodes of extinction and recolonization, and that documented patterns of population subdivision are the outcome of recent and multiple refugia. We discuss the evolutionary history of the species with particular interest in the increasing relevance of Mediterranean refugia for the survival of genetically differentiated populations during the Pleistocene glaciations as revealed by studies in co‐distributed taxa.     

欧报春（Primula vulgaris）不同花色与色素关系及花色遗传初步分析

为了掌握欧报春各花色遗传规律服务于良种生产,通过对欧报春各色花进行色素吸收光谱和薄层层析分析,进行不同花色杂交研究,分析了欧报春各色花所含色素类型及各花色遗传规律。结果显示欧报春群体含多种花色素,单株也可含有多种花色素,形成多变的粉色、红色及蓝色花。黄色深浅主要由类胡萝卜素含量决定。白色对粉色及黄色为隐性遗传,黄色、粉色为显性遗传并有数量遗传特征,黄色与粉色独立遗传。蓝色为多基因控制的隐性遗传,并具有数量遗传特征。     

Fish and dragonfly nymph predators induce opposite shifts in color and morphology of tadpoles

Many prey species, including amphibian larvae, can adaptively alter coloration and morphology to become more or less conspicuous to predators. Despite abundant research on predator-induced plasticity in tadpoles, the combination of color and morphological responses to predators remains largely unexplored. We measured predator-induced morphological and color plasticity in tadpoles. We reared tadpoles of the neotropical treefrog Dendropsophus ebraccatus with dragonfly nymph or fish predators, or in a predator-free control. After 10 days, we digitally photographed tadpoles and measured eight morphometric variables and five tail color variables. Tadpoles reared with nymphs developed the largest and reddest tails, but incurred a developmental cost, being the smallest overall. Cues from fish induced an opposite tail phenotype in tadpoles, causing shallow achromatic tails. Control tadpoles developed intermediate tail phenotypes. This provides the first experimental evidence that tadpoles can shift both color and morphology in opposite, predator-specific directions in response to a fish and an odonate predator. Despite mean differences, however, there was substantial variation in the degree of phenotype induction across treatments. Tail redness was correlated with tail spot size, but not perfectly, indicating that color and morphology may be partially decoupled in D. ebraccatus . Balancing selection from multiple conflicting predators may result in genetic variation for developmental plasticity.     

Optimization, constraint, and history in the evolution of eyes

Several features of the evolution of eyes and photoreceptors are examined in an effort to explore the relative roles of adaptation and historical and developmental constraints. Optical design shows clear evidence of adaptation, which in some respects approaches optima predictable from physics. The primate fovea, on the other hand, illustrates how adaptation can be channeled by developmental heritage. The primary structures of opsins reveal multiple evolutionary lineages within both Drosophila and humans. The pigments of vertebrae rods comprise a subset of opsins whose evolutionary relationships map onto the phylogeny of the parent species. The evolutionary reasons for why most rod pigments absorb maximally at 500 +/- 10 nm are obscure, as there is no convincing explanation based on adaptation alone. Rods are appropriately distinguished from cones on the basis of which opsin gene is expressed. This criterion is likely to be in conflict with other definitions in phyletic lines (e.g., geckos, snakes) that have long diurnal or nocturnal histories accompanied by loss of one or more opsin genes, followed by a secondary adaptation to life in a different photic environment. Color vision--a generalizable perception associated with the spectral composition of light--is usefully distinguished from wavelength-specific behaviors. The latter are also based on multiple visual pigments and more than one spectral class of receptors but cannot be altered by learning. The distinction is particularly forceful in bees, which exhibit both kinds of behavior. The evolution of primate color vision has been shaped by historical factors involving an extensive period of early mammalian nocturnality. Birds, by contrast, have more elaborate cones and a richer set of visual pigments. Avian color space can be represented in a tetrahedron.     

The biology of the golden hammerhead,Sphyrna tudes,off Trinidad

Synopsis The golden hammerhead is a poorly known species of shark that inhabits the northeastern coast of South America from Venezuela to Uruguay. It is found in coastal waters at depths of 9–40 m over muddy bottoms. It is a small species which attains a maximum size of 122 cm and 9 kg. The most distinctive characteristic of this species is its striking bright orange or yellow color. Juveniles less than 80 cm TL are bright yellow or orange; adults are pale yellow. The color is apparently due to pigments present in their diets; juveniles feed primarily on shrimp, while adults feed on fish and catfish eggs. Two pigments have been isolated and their characterization is presently being ascertained. Males mature at about 80 cm TL; females mature at about 98 cm TL. Ovulation and mating occur in August. Gestation appears to last about ten months. Parturition occurs in shallow waters from late May to June. Broods consist of five to twelve young, which measure about 30 cm at birth. The ovarian cycle runs concurrently with the gestation cycle, so it is likely that females are fertilized shortly after parturition, and that the species reproduces yearly.     

Carotenoid pigments in rust fungi: Extraction,separation, quantification and characterisation

Diseases caused by rust fungi represent critical constraints to global plant production. A characteristic feature of rust pathogens is the striking pigments they produce in one or more spore forms, which give them a rusty appearance. Here, we review the literature published to date on the extraction, separation, quantification and characterisation of carotenoid pigments in rust fungi. These pigments are thought to protect rust fungi against UV radiation and oxidative stress, and possibly act as virulence factors. The yellow-orange colour of some rust species is due to carotenoid pigments. Four carotenoids have been found in rust fungi: phytoene, lycopene, γ-carotene and β-carotene, but their relative contributions to biological functions are largely unknown. Different pre-processes and storage of spore materials, as well as different extraction processes, have been applied in a wide range of investigations on rust spore pigments. We find that the value of the current literature on rust carotenoids for taxonomic diagnostics in understanding the evolution of pigment biosynthesis and in assessing their role in pathogenesis is limited. Re-investigation of rust carotenoid composition using modern analytical technologies is therefore critical to further these fields of research. Our review includes detailed guidance on choice of techniques for rust carotenoid experimental analyses.     

Molecular cloning of cDNA encoding red opsin gene in the retinas of five Antarctic notothenioid fishes

Previous evidence suggested that notothenioid fish had lost red-sensitive (LWS) visual pigment and photoreceptors, but retained ultraviolet-sensitive (SWS1), blue-sensitive (SWS2), and green-sensitive (RH2) pigments. We used RT-PCR and Southern blot to isolate the LWS opsin gene in five notothenioid species. We determined full-coding LWS opsin sequences and genomic sequences. The expected peak absorbance of the LWS opsin, based on the five-sites rule that is primarily responsible for the spectral sensitivities in vertebrates, ranged from 541 to 553 nm. In Antarctic waters, light of this wavelength penetrates to dozens of meters. Thus, we conclude that notothenioids use tetrachromatic color vision in shallower waters, at least during the Antarctic summer.     

Secondary metabolite profile and phytotoxic activity of genetically distinct forms of Colletotrichum gloeosporioides from yam (Dioscorea spp.)

Highly virulent, slow-growing grey (SGG); moderately virulent, fast-growing salmon (FGS); and avirulent/weakly virulent, fast-growing grey (FGG) forms of Colletotrichum gloeosporioides have been described from yam (Dioscorea spp.), but little is known about their chemodiversity or the role of toxins in their pathogenesis. Secondary metabolite profiles in high performance tlc (hptlc) showed that the pathogenic SGG and FGS forms have a chemotype (A or B) that is distinct from the non-pathogenic FGG form (chemotype C). Crude extracts of 35-d-old Czapek-Dox yeast broth cultures of FGS and SGG isolates caused tissue necrosis on treated yam leaves but not those of FGG isolates. Extracts from uninoculated broth cultures showed no phytotoxic activity. Toxicity of the culture filtrate was not host specific and toxic substances were thermostable. Dioscorea genotypes with varying levels of resistance to anthracnose differed in their sensitivity to crude toxin extract of FGS (Cg33) and SGG (Cg25) isolates, indicating that these extracts may be useful in evaluating host resistance to anthracnose in vitro. Analysis of two toxin fractions unique to the pathogenic FGS and SGG forms using hlpc, mass spectrometry and nuclear magnetic resonance suggested the presence of a low molecular weight amide peptide. However, possibly due to low yield and the presence of impurities, the chemical structure of the compound(s) could not be fully elucidated.     

The last terror birds (Aves,Phorusrhacidae): new evidence from the late Pleistocene of Uruguay

We report new fossil evidence of terror bird survival until the end of the Pleistocene in Uruguay. The new specimens comprise the distal portion of right tarsometatarsus and a left humerus; the latter is assigned to the genus Psilopterus. The sedimentary context of the remains yields a characteristic Pleistocene mammalian association along with numerical age dating giving an undoubted late Pleistocene age (OSL 96,040 ± 6300 years). We also revise and discuss the systematic placement of late Pleistocene phorusrhacid material previously published. The trophic role of terror birds and other South American carnivorous birds in late Pleistocene ecosystems should be revised based on the increasing findings of avian fossil materials.