AERODYNAMICS,THERMOREGULATION, AND THE EVOLUTION OF INSECT WINGS: DIFFERENTIAL SCALING AND EVOLUTIONARY CHANGE

We examine several aerodynamic and thermoregulatory hypotheses about possible adaptive factors in the evolution of wings from small winglets in insects. Using physical models of Paleozoic insects in a wind tunnel, we explore the potential effects of wings for increasing gliding distance, increasing dispersal distance during parachuting, improving attitude control or stability, and elevating body temperatures during thermoregulation. The effects of body size and shape, wing length, number, and venation, and meteorological conditions are considered. Hypotheses consistent with both fixed and moveable wing articulations are examined. Short wings have no significant effects on any of the aerodynamic characteristics, relative to wingless models, while large wings do have significant effects. In contrast, short wings have large thermoregulatory effects relative to wingless models, but further increases in wing length do not significantly affect thermoregulatory performance. At any body size, there is a wing length below which there are significant thermoregulatory effects of increasing wing length, and above which there are significant aerodynamic effects of increasing wing length. The relative wing length at which this transition occurs decreases with increasing body size. These results suggest that there could be no effective selection for increasing wing length in wingless or short-winged insects in relation to increased aerodynamic capacity. Our results are consistent with the hypothesis that insect wings initially served a thermoregulatory function and were used for aerodynamic functions only at larger wing lengths and/or body sizes. Thus, we propose that thermoregulation was the primary adaptive factor in the early evolution of wings that preadapted them for the subsequent evolution of flight. Our results illustrate an evolutionary mechanism in which a purely isometric change in body size may produce a qualitative change in the function of a given structure. We propose a hypothesis in which the transition from thermoregulatory to aerodynamic function for wings involved only isometric changes in body size and argue that changes in body form were not a prerequisite for this major evolutionary change in function.     

安徽巢县发现的人类枕骨化石和哺乳动物化石

1982年在安徽巢县银山发现的化石材料表明,该地点下部堆积的时代为早更新世,上部堆积的时代相当于北京猿人地点的1—4层或稍晚。一块人类枕骨化石出自上部堆积,代表一青年女性个体,很可能是属于早期智人的杭骨。该地点的动物群具有东洋界和古北界的色彩。     

论扬子区中晚奥陶世和志留纪四射珊瑚的分类及一些科属的演化

扬子区中奥陶世至早、晚志留世产有丰富的四射珊瑚,尤其Ashgill期中、晚期和Llandovery世的Aero-nian—Telychian期产出珊瑚最盛。据已报道统计,该地区共有四射珊瑚124属,包括中、晚奥陶世31属,早志留世(Llandovery世)87属,晚志留世6属。其中有一些属的分类位置以及属征各家仍存在分歧。对扬子区中、晚奥陶世和志留纪四射珊瑚群已发表和笔者手中尚存资料进行系统整理之后,提出该区奥陶纪、志留纪四射珊瑚的分类意见并加以讨论,共分3个目:即扭心珊瑚目(Streptelasmatida),柱珊瑚目(Columnariida)和泡沫珊瑚目(Cystiphyllida)。其中扭心珊瑚目含有46属,分属7个科,柱珊瑚目包含37属,分属14个科,而泡沫珊瑚目包含41属,分属9个科。此外,文中提出扬子区中、晚奥陶世和早志留世四射珊瑚某些科、属的演化趋向并加以适当讨论。     

TRACE FOSSILS FROM THE PRECAMBRIAN AND BASAL CAMBRIAN

Certain worm-like configurations on rocks are recognized as shrinkage-crack infillings. Some genuine Precambrian trace fossils are briefly described. The early Cambrian contains a richer assemblage, including some distinctive and widespread form genera. The study of early trace fossils leads to conclusions not only on facies, but also on the evolution of behaviour and functional morphology in soft-bodied organisms.     

记甘肃东乡汪集的板齿犀和三趾马化石

汪集的板齿犀化石和周明镇1958年所定的“Sinotherium”simplum,在大小、齿冠高度和构造上都很接近,应归为同种。它们和Sinotherium的属型种,S.lagrelii,有明显的差别,而和Killgus于1923年所定的Parelasmotheriumschansiense更为接近。笔者认为Parelasmotherium属应予恢复。“Sinotherium”simplum应该改称为Parelasmotheriumsimplum。汪集新发现的Hippariondongxiangense是我国已知三趾马中牙齿尺寸最小的。汪集含上述化石的地点的地质时代可能是晚中新世的早期。     

18S rDNA AND EVOLUTION IN THE DASYCLADALES (CHLOROPHYTA): MODERN LIVING FOSSILS1

Phylogenetic relationships were inferred from parsimony and distance analyses of nuclear small-subunit ribosomal DNA sequences taken from 14 species representing 8 of the 11 extant genera in the Dasycladales. Of 1733 aligned positions, 412 (23.8%) were variable and 251 (61%) of those were phylogenetically informative within the Dasycladales. Secondary structure was analyzed and taken into account during all phases of data analysis. Robustness of the trees was assessed using bootstrap analysis and g₁ statistics of tree-length decay. Strongly supported branches were robust to all methods of analysis regardless of weighting schemes used. The secondary structure of the 18S within the Dasycladales agrees with that of other green algae with the exception of a shared deletion in stemloop E10-1 (ca. 13 nucleotides long), which provides additional support for the uniqueness of this monophyletic group. A molecular clock was calibrated from the dasyclad fossil record and suggests a radiation of the Acetabulariaceae at 120 ± 30 million years (Ma) ago and the Dasycladaceae 215 ± 40 Ma ago. The split of the two lineages from a shared ancestor is estimated at 265 ± 50 Ma ago. Within the Dasycladaceae, Neomeris and Cymopolia are sister taxa, as are Batophora and Chlorocladus. Bornetella groups with the Neomeris and Cymopolia clade in 78% of the bootstrap replicates. Relationships among the Acetabulariaceae show that Acetabularia and Polyphysa do not form monophyletic groups as presently circumscribed. No evidence indicates that Acicularia is the oldest genus. Halicoryne, Chalmasia, and Dasycladus were not included in the analysis. Molecular data provide afresh background perspective from which to discuss the evolution of one of the most ancient lineages of green plants.     

北京云水洞的脊椎动物化石

标本包括鸟类一新种Phasianus yanshansis sp.nov.、啮齿类一种、奇蹄类一种、偶蹄类两种。地质时代为更新世晚期,碳~(14)测定是18,540±250年,与周口店山顶洞相当。     

COLD-TOLERANT FERMENTATIVE GRAM-NEGATIVE ORGANISMS FROM MEAT AND OTHER SOURCES

SUMMARY: From various chilled meats, twenty-eight strains of coli-aerogenes bacteria and one Aeromonas were isolated which grew well at +1±5° and some at −1±5°. The optimum growth temperature for most of these strains was nearer 37° than 30°. Nine strains (including the Aeromonas ) fermented lactose rapidly, the remainder slowly or not at all. All the strains which fermented lactose rapidly with the production of gas gave positive presumptive coli-aerogenes tests in MacConkey's broth at 30°, but only five were positive at 37°; none was positive at 44°. Because such organisms can attain populations of millions/cm², they could confuse the interpretation of presumptive coli-aerogenes tests made on chilled meat.     

论中国早寒武世原牙形类和牙形状化石——分类评述和地层意义

原牙形类和牙形状化石是早寒武世微小骨骼化石中非常特征的一个类群。自二十世纪70年代以来,这些齿状的微型磷质骨片化石在中国下寒武统含小壳化石地层中被大量发现,据统计已描述有25属52种。通过文中的评述和讨论,证实其中的一些属种是次异名或属于无效的分类名称,还有一些在归属上尚存在疑问。通过对原牙形类和牙形状化石定义的讨论,将先前指定为原牙形类的13个属进行了分类评述。表明其中的5个属是次异名,还有2个属是未知的节肢动物。其它的12个牙形状化石属中也有5个属是次异名,它们不仅显示了有多种动物亲缘的牙形状形态,而且大多属于绝灭生物,只有Beshtashella和Paraformitchella(=Beshtashella)被指定为软体动物。文中还简要地讨论了大多数属的时空分布,包括3个阶段的原牙形类地层分布,这不仅具有划分对比地层的意义,而且还反映了原牙形类的演化趋势。     

甘肃临夏盆地牙沟的哺乳动物化石及有关地层问题

记述了临夏盆地牙沟地点除巨犀以外的 8类哺乳动物化石 :Tsaganomysaltaicus、Mega lopterodonsp .、Schizotheriumordosium、Hyracodontidaegen.etsp .indet.、Ardyniaaltidentatasp .nov.、Ardyniasp .、Aprotodonlanzhouensis和Paraentelodoncf.P .macrognathus。新种Ardyniaalti dentata的主要特征是 :个体大 ,齿冠高 ;M2冠高大于冠长 ,“小刺”异常发育 ,后脊退缩 ;下臼齿下三角座变短 ,外中沟位于齿长的前 1 /3处。牙沟、椒子沟和毛沟底部地层中所发现的哺乳动物化石均产自同一层位 ,其时代为晚渐新世 ,而不是早中新世。含化石的地层属椒子沟组。李吉均等所建中庄组应予废除     

中国新近纪牛科分类及演化规律

我国新近纪的牛科相当繁盛。至今已记录了30属,归入5个亚科(Hypsodontinae,Urmiatheriinae,Caprinae,Antilopinae和Bovinae)。化石主要出现在我国北方且大部分为土著类型,以颊齿中等高冠至高冠、前臼齿列短、头骨粗壮、弯曲和角心特化为特征。在整个新近纪时期,牛科经历了5个发展阶段和4次大的更替。与同时代欧亚大陆其他地区的牛科类群相比,中国牛科化石出现的时间早,且基本组成不同。在中新世,我国的牛科主要由Hypsodontinae,Urmiatheriinae,Caprinae的早期特化类型和Gazella组成,Boselaphini稀少并缺乏转角羚羊(Antilopinae);在上新世,除Gazella外,我国北方仍生活着Caprinae的一组土著类型。     

PREDICTING DESICCATION STRESS IN MICROSCOPIC ORGANISMS THE USE OF AGAROSE BEADS TO DETERMINE EVAPORATION WITHIN AND BETWEEN INTERTIDAL MICROHABITATS1

We describe an easy and inexpensive way to determine whether intertidal microhabitats remain wet during tidal emersion. This new technique uses agarose beads (120 üm diameter when fully hydrated) that shrink in a graded fashion as they dry. The agarose beads allow variability in surface wetness to be gauged over distances of less than 1 mm. Describe this parameter of microclimate is important in order to predict the likelihood and spatial pattern of survival of settled larvae, reproductive propagules, and other microscopic stages in the life histories of organisms growing in intertidal and other water-stressed environments. For the brown seaweed Pelvetia fastigiata (J. Ag.) DeToni (Fucales, Phaeophyta), the use of agarose beads demonstrated that survival of zygotes during tidal emersion was highes at those sites that remain damp. Temperature alone was found to be an unreliable measure of wetness within a single microhabitat (e.g. red algal turf).     

云南禄丰古猿地点Ursinae indet.化石性质的再讨论

1984年和1985年本文后一作者曾将禄丰古猿化石地点的一种小型而冠面无强烈褶皱的熊类化石归人Ursinae indet.现经重新研究,认为它应属Ursavus。鉴于它和Utsavus已知其他种的区别,订一新种U.sylvestris。它与欧洲的U.ehrenbetgi大体处在同一进化水平上。在原认为是Ursinae indet.的材料中,有两枚M_1,其特点与U.sylvestris者不同,暂以Ursavus sp.记之。     

新疆下寒武统玉尔吐斯组软舌螺口盖和口盖状化石

文中系统描述了新疆乌什－阿克苏地区下寒武统玉尔吐斯组软舌螺口盖和口盖状化石５属７种,其中包括２新属３新种。Ｘｙｓｔｒｉｔｈｅｃａ的口盖具有复杂的锁骨构造,Ｐａｃｈｙｔｈｅｃａ的口盖有明显的背腹扇面之分,它们与具口唇的软舌螺Ｍｉｃｒｏｃｏｒｎｕｓ共生。这些演化上较高级的软舌螺与原牙形类Ｊｉａｎｇｓｈａｎｏｄｕｓ,Ｇａｐｐａｒｏｄｕｓ,Ａｍｐｈｉｇｅｉｓｉｎａ;假牙形类Ｒｈｏｍｂｏｃｏｒｎｉｃｕｌｕｍ     

PHYLOGENIES AND THE ANALYSIS OF EVOLUTIONARY SEQUENCES,WITH EXAMPLES FROM SEED PLANTS

Studies of character evolution have frequently relied on ahistorical correlations rather than on phylogenies. However, correlations do not estimate the number of times that a trait evolved, and they are insensitive to the direction or the temporal sequence of character transformation. In contrast, cladograms can provide this information. A cladistic test of the hypothesis that the evolution of dioecy is favored in animal-dispersed plants indicates that dioecy may have originated somewhat more often in such lineages. Nevertheless, differences in rates of speciation or extinction must largely account for the observed species-level correlation between dispersal and breeding system. In considering the evolution of individual traits, cladograms help identify the context in which a feature evolved and specify which organisms should be compared in evaluating the causes of character change. Determining whether a feature and a performance advantage were strictly historically correlated or followed one another in sequence helps to distinguish whether the trait is an adaptation or an exaptation for the function. For example, cladograms of seed plants suggest that double fertilization arose incidentally prior to the origin of angiosperms and that the resulting product was later co-opted and elaborated as a nutritive tissue for the developing embryo. The order of character assembly in a lineage also bears on the evolution of functional and developmental interdependencies. In particular, it may be possible to trace the evolution of a character's “burden” from an initial period, during which change is more likely, through later stages, wherein successful modification is less likely owing to the evolution of dependent characters. The evolution of vessels and of floral phyllotaxis in angiosperms may exemplify this pattern. Recognition that the likelihood of character transformation may change during the evolution of a group warns against character weighting in phylogenetic analysis.     

甘肃榆中晚更新世哺乳动物化石

本文记述了甘肃榆中上苦水大沟发现的几种哺乳动物化石：Microtusgregalis,Ochotonasp.,Felistigris,Equusprzewalskii,Coelodontaantiquitatis,Cervus（Sika）sp.,Antilopinaegen.indet.,Ovisnahoor,Bovinaegen.indet..含化石地层的时代应为晚更新世中晚期。这是甘肃中部地区新发现的一个层位确切、化石门类较多的第四纪哺乳动物群。