中国中生代鸟类的体重估计及其演化趋势

体重是一项重要的生物学指标,生物的体重受到发育、繁殖和进化等诸多因素的影响。对于灭绝生物体重的估计有助于进一步恢复它们的各种生物学信息。本研究采用统计学的方法,对422件现生鸟类(分属于21目229种)的体重和18项骨骼量度指标分别进行一元回归分析,结果显示判定系数的分布范围在0.5～0.91之间,多数指标的判定系数均集中在0.8～0.9之间。采用另外64件测量有体重数据和骨骼量度的鸟样本对回归方程的估算准确率进行检验,发现前肢中肱骨长度和尺骨宽度以及后肢中胫跗骨宽度3项指标的估算准确率高于其他指标。分析结果还表明前肢两项指标对于估算鸣禽、猛禽和攀禽类等树栖鸟类的体重准确率较后肢显著;后肢指标对于估算陆禽类等地栖鸟类体重的准确率高于前肢指标。这一结果反映出与体重相关程度较高的骨骼量度指标在不同习性的鸟类当中存在着一定的差异。对于化石鸟类的体重估计,采用估算准确率较高并且便于测量的肱骨长度和胫跗骨宽度两项回归方程加以计算。通过对中国中生代鸟类的体重进行估算,结果显示中生代鸟类在系统发育过程中,反鸟类经历了体重逐渐减轻的过程,而今鸟类的体重开始不断增大并且出现显著的分异。     

中国中生代鸟类后肢骨骼的长度比例特征及栖息习性的分析

通过对18目59科137例现生不同栖息习性鸟类的后肢3块骨骼(股骨、胫跗骨和跗跖骨)长度比例的观察和特征分析,推断出鸟类的栖息习性与后肢3块骨骼中各骨骼长度所占总长度的比例存在密切的关系。即在所有鸟类的后肢骨骼中,胫跗骨的长度占3块骨骼的比例为最大;地栖鸟类后肢骨骼中股骨的长度要短于跗跖骨;树栖鸟类后肢骨骼中股骨的长度要长于跗跖骨。鸟类后肢3块骨骼的长度比例特征是鸟类长期对栖息等行为适应的结果。在此基础上,对中国中生代14例鸟类的栖息习性进行了分析,利用三元投影的统计方法,并以国内外新生代(古近纪和新近纪)21例鸟类标本作为对比参考,得出辽西中生代不同类型鸟类的栖息行为特征:基干鸟类以树栖为主要习性,其中个别鸟类还具有攀援的习性,而反鸟类则是典型的树栖鸟类,今鸟类兼有树、地栖的习性。研究表明,在现行的鸟类系统发育框架下,树栖适应(及攀援)代表了鸟类演化历史中最原始的生活方式。这一结论也支持鸟类飞行的树栖起源假说。中生代鸟类栖息习性分异的多样性反映了早期鸟类演化过程中自身以及与其他同期生物在生态空间和食物资源的竞争的加剧和对环境的不断适应。     

中国北方化石昆虫群的建立及其演化序列(英文)

作者几十年来已积累了众多的中国北方古生代晚期、中生代和第三纪的昆虫化石标本,对其长期的系统研究结果表明：中国北方昆虫化石演化序列可以划分为三个大的演化阶段,即古生代晚期、中生代和第三纪演化阶段,其中包含14个昆虫群虫和29个昆虫组合。这些昆虫群及其组会既反映了北方昆虫在地质历史上兴衰的发展规律,也为地层划分、对比与地质时代的鉴定提供了依据。     

ESTABLISHMENT OF FOSSIL ENTOMOFAUNAS AND THEIR EVOLUTIONARY SUCCESSION IN NORTH CHINA*

Abstract According to a systematic study of large numbers of fossil insects collected from the Paleozoic, Mesozoic and Tertiary strata in North China, three evolutionary mega-stages of fossil insects including 14 fossil entomofaunas and 29 entomassemblages have been established. These insect faunas reflect their order or law of evolution—the history of their rise and fall, and form their evolutionary succession in North China. Such a history provides an important reference not only for understanding fossil insects through time, but also showing for stratigraphical correlation.     

PERSPECTIVE: EVOLUTIONARY PATTERNS IN THE FOSSIL RECORD

The study of large-scale evolutionary patterns in the fossil record has benefited from a diversity of approaches, including analysis of taxonomic data, ecology, geography, and morphology. Although genealogy is an important component of macroevolution, recent visions of phylogenetic analysis as replacing rather than supplementing other approaches are short-sighted. The ability of traditional Linnaean taxa to document evolutionary patterns is mainly an empirical rather than a theoretical issue, yet the use of these taxa has been dismissed without thorough evaluation of their empirical properties. Phylogenetic analysis can help compensate for some of the fossil record's imperfections. However, the shortcomings of the phylogenetic approach have not been adequately acknowledged, and we still lack a rigorous comparison between the phylogenetic approach and probabilistic approaches based on sampling theory. Important inferences about the history of life based on nongenealogical data have later been corroborated with genealogical and other analyses, suggesting that we risk an enormous loss of knowledge and understanding if we categorically dismiss nonphylogenetic data.     

中国夹竹桃目的形态演化趋势及其进化系统

本文探讨了中国夹竹桃目主要器官分类性状的进化趋势,发现了中国夹竹桃目有关花萼、花冠、副花冠、雄蕊、花粉、子房和果实等分类性状密切关系和演化的规律性(图1),从而在作者参考蒋英教授工作成就的基础上,提出了中国夹竹桃目各分类群的进化系统(图2)。     

SIDEWAYS-THROWING AND SIDEWAYS-BUILDING IN BIRDS

Birds which build the simplest and scantiest nests use a single movement, sideways-throwing, in assembling material; and a modified form of it, sideways-building, in arranging material on the site. Sideways-throwing is usually performed by a standing or walking bird which picks up a small object in front of it, and throws it back, either to one side or beneath it, with a sharp sideways movement of the head. Sideways-building is normally performed by a sitting bird which takes material and deliberately places it to either side or in towards its breast. Sideways-throwing and sideways-building occur in the Struthionidae, Rheidae, Dromaiidae, Gaviformes, Procellariformes, Anseriformes, Meleagrididae, Phasianidae, Gruidae and Charadrüformes. Sideways-building only is recorded in the Sulidae ahd, for Platalea leucorodia, in the Threskiornithidae. There are no records of nest-building in the Apterigidae, Tinamidae, Otidae, and Pteroclididae. Sideways-throwing occurs within the vicinity of the nest-site, often in conjunction with conflict behaviour; and typically occurs at nest-relief, performed by the bird leaving the nest. This results in material accumulating at the nest-site, and this may be pulled in by the sitting bird during sideways-building, The amount and type of material depends on its availability around the nest-site. In species where only one sex incubates the sitting bird may leave the nest at intervals and perform sideways-throwing. Sideways-throwing appears to occur frequently as a form of irrelevant behaviour, usually in agonistic situations; sideways-building often occurs when a sitting bird is disturbed. Since sideways-throwing is a relatively ineffectual form of nest-building, the creation of a nest appears to depend on the extent to which the bird finds itself in a conflict situation and the amount of material near the nest. It seems possible that it may have evolved as Irrelevant Behaviour rather than true nest-building. It is suggested that the movements might be derived from false-feeding movements involving the picking up of inedible objects, and from the flick of the head, with which a bird removes an unwanted object adhering to its bill. Such behaviour performed by a bird walking repeatedly from the nest could result in the accumulation of material at a nest-scrape. Relatively little modification would be needed to create a form of nest-building suitable for very simple nests. Chance sideways-throwing seems to occur in many species. Nests in damp situations may be larger than those in dryer ones and, although this might be accidental, the behaviour of some species during floods suggests purposeful building. Some species appear to align their throwing in relation to the position of the nest. In some groups within the Charadrüformes sideways-throwing appears to have been replaced by the carrying of material to the nest. In such species relict sideways-throwing often occurs when material is deposited on the nest-site; and sideways-building is used in the arrangement of the material. It is possible that movements similar to sideways-building used in nest construction by birds in other groups might be homologous with it and represent the persistence of an earlier behaviour pattern.     

东北地区中生代化石木异木属及其古生态

迄今为止,我国共了现异木属（Ｘｅｎｏｘｙｌｏｎ）化石木１０种（包括２新种）,它们是Ｘ．ｌａｔｉｐｏｒｏｓｕｍ,Ｘ．ｃｏｎｃｈｙｌｉａｎｕｍ,Ｘ．ｌｉａｏｎｉｎｇｅｎｓｅ,Ｘ．ｊａｐｏｎｉｃｕｍ,Ｘ．ｅｌｌｉｐｔｉｃｕｍ,Ｘ．ｈｏｐｅｉｅｎｓｅ,Ｘ．ｐｅｉｄｅｎｓｅ,Ｘ．ｙｉｘｉａｎｅｎｓｅ,Ｘ．ｆｕｘｉｎｅｎｓｅ ｓｐ．ｎｏｖ．,Ｘ．ｈｕｏｌｉｎｈｅｎｅｓｅ ｓｐ．ｎｏｖ．。文中对该属的古生态作了     

STRATOCLADISTICS AND EVALUATION OF EVOLUTIONARY MODES IN THE FOSSIL RECORD: AN EXAMPLE FROM THE AMMONITE GENUS SEMIFORMICERAS

Abstract:  At least two predominating modes of evolution have been proposed for the Early Tithonian oppeliid ammonite genus Semiformiceras , including phyletic transformation of a single lineage ( S. darwini – S. semiforme – S. fallauxi ) and, most recently, a bifurcating or cladogenetic model of speciation. We discuss methodological obstacles in past studies that have focused on specific modes of evolution, and offer a reanalysis of the morphological data first presented by Cecca and Rouget [ Palaeontology , 49 , 1069–1080] using the stratocladistic software StrataPhy. The present analysis utilizes 11 ammonite taxa and 15 characters (14 morphological and one stratigraphic) and assesses all previous phylogenetic hypotheses, including those that recruit OTUs in ancestral or 'nodal' positions, without excluding evolutionary modes. The results cast doubt on the monophyly of S. darwini , S. semiforme and S. fallauxi , but do not follow completely the direct anagenetic progression proposed by stratophenetic hypotheses. We conclude that stratocladistics is a helpful tool for elucidating the extent of anagenesis and cladogenesis in extinct lineages owing to its capacity to reconstruct phylograms in their temporal framework, and to assess the distinctness and monophyly, not just of clades but of the OTUs themselves. Ultimately, this study addresses the novel utility of computer-assisted stratocladistic analysis in assessing evolutionary modes beyond the reach of traditional cladistic-based methodologies.     

A DEVELOPMENTAL ANALYSIS OF AN EVOLUTIONARY TREND: DIGITAL REDUCTION IN AMPHIBIANS

In this study, we integrate information from phylogeny, comparative ontogeny, and experimental embryology in an attempt to elucidate the mechanisms controlling evolutionary trends towards digital reduction and loss observed in amphibians. Frogs and salamanders that have lost phalanges and even whole toes have done so in a very ordered manner, i.e., certain skeletal elements are lost prior to others. This pattern of morphological diversity is described and trends elucidated. It is concluded that the process is characterized by striking intraordinal convergences coupled with substantial differences between the trends observed in frogs as compared to urodeles. We argue that this pattern is essentially a reflection of the differences in the ontogenies of the two orders. Similarly, the convergences within urodeles and within anurans can be explained as the result of regulation of developmental parameters in a resilient developmental program. We further explore this hypothesis by experimentally perturbing the number of cells in the embryonic limb primordium to show that reduction in the number of mesenchymal cells secondarily affects the developmental process of pattern formation causing a rearrangement of the skeletal morphology of the foot. The same experimental manipulation has different effects in frogs as compared to salamanders. However, in both cases, the experimentally generated morphologies tend to parallel the phenotypes and trends observed in nature. Our conclusion is that most of the patterns of diversity in the digital morphology of amphibians can be explained as a reflection of developmental properties. In general, we present a methodology that attempts to empirically address the issue of identifying developmental constraint in morphological evolution.     

OLFACTORY-BULB SIZE AND NOCTURNALITY IN BIRDS

Recent evidence shows that, despite earlier beliefs, many birds have a functional sense of smell. There is also considerable variation in olfactory-bulb size among bird species, yet the evolutionary significance of this variation has remained elusive. We argue that birds living under low-light conditions, where vision is less efficient, should have evolved or maintained an increased olfactory ability and, hence, larger olfactory bulbs. Using a family-level comparative analysis to control at least partially for taxonomic artifacts, we show that none of a series of ecological variables (diet, nest type, development, nest dispersion, and migratory behavior) accounts for variation in olfactory-bulb size once the effects of body size and brain size (measured by cerebral-hemisphere length) have been controlled. Activity timing, however, accounts for significant variation even after the removal of these other variables. We discovered 13 independent cases in which nocturnal or crepuscular lineages have evolved a diurnal habit, or vice versa, and compared relative olfactory-bulb sizes between each branch pair. In all but one case, nocturnal or crepuscular birds have larger olfactory bulbs than their diurnal counterparts. We therefore demonstrate a widespread relationship between ecology and the evolutionary development of a part of the brain.     

中国汉族儿童生长的长期趋势

本文报告了中国北京、天津、济南、哈尔滨、沈阳、长春、上海、南京、杭州、武汉、广州及成都等12个城市汉族7—18岁儿童生长的长期趋势。 50年代至今,汉族儿童生长的长期趋势是明显的,30年来同年龄儿童身高每10年增长2.66(男)、2.40(女)厘米,体重每10年增长1.64(男)、1.14(女)公斤,近10年来的增长最为显著。生长突增高峰年龄大都提前1—2年。北京、上海、南京、广州、杭州等五所城市自30年代至今,生长长期趋势也是明显的,半个世纪来,每10年增长值,男童身高为1.12—2.66厘米,体重为0.56—1.29公斤,女童身高为1.42—2.67厘米,体重为0.65—1.18公斤。     

中国大陆与台湾画眉亚科鸟类渊源初探

中国现有画眉亚科鸟类１３１种,占世界种数（２８２种）４７％,其中有１３种为海峡两岸（大陆与台湾）共有。海峡两岸画眉类鸟类的分布有两种情况：连续性分布或间断性分布。这种既连续又间娄的分布特点,表现在来眉类鸟类在海峡两的种内及种间的差异上,同时也体现了台湾与东喜巴拉雅地区之间来眉类鸟类的亲缘关系。在地持、气候、植被环境等诸多因素历史变迁的共同影响下,形成了画眉类鸟类在台湾岛上特有的５个种及１２个亚种。     

蚜类昆虫化石属种划分和描述中的问题

对我国“热河生物群”中蚜类属种进行全面评述,Ｓｉｎａｐｈｉｓ,Ｔａｒｔａｒａｐｈｉｓ不应与Ｐｅｎａｐｈｉｓ合并;Ｐａｒｏｖｉｐａｒｏｓｉｐｈｕｍ,Ｍｅｓｏｖｉｐａｒｏｓｉｐｈｕｍ不应与Ｏｖｉｐａｒｏｓｉｐｈｕｍ合并,Ｐ．ｏｐｉｍｕｍ不应与Ｐ．ｃａｍｐｔｏｔｒｏｐｕｍ合并,Ｍ．ｔｕａｎｗａｎｇｅｎｓｅ不能与Ｍ．ｍａｌａｃｕｍ合并;Ｃａｕｄａｐｈｉｓ不能与Ｅｌｌｉｎａｐｈｉｓ合并,Ｃ．ｌｅｐｔｏｎｅｕ     

SPECIATION AND FEATHER ORNAMENTATION IN BIRDS

The hypothesis that sexual selection promotes speciation has rarely been tested. We identified 70 evolutionarily independent events of feather ornaments in birds. For each focal species we noted the number of ornamented and nonornamented species belonging to its genus and its number of subspecies, as well as its mating system and the extent of its geographic range. For purposes of comparison, we randomly chose a second, nonornamented species for which we obtained information on the number of subspecies, and in cases in which the nonornamented species was in the same genus, we chose a third, nonornamented species in a related genus and obtained the same information. We then noted the number of species in each genus and the difference in numbers of species, or species richness, between paired genera. For the genera of the focal ornamented species, we regressed number of ornamented species on number of nonornamented species and found a positive relationship. As number of species per genus rose, number of ornamented species per genus rose more rapidly, indicating that more speciose genera have a higher proportion of ornamented species than less speciose genera. We then took the deviations from this regression, the residual number of species, and regressed them on the differences in species richness between the paired genera. This relationship was positive indicating that ornamented genera with more than the expected number of ornamented species were more speciose with respect to their paired genera than were genera with fewer than the expected number of ornamented species. Finally, we compared the deviations from this regression, the residual number of ornamented species, with species' mating system and found a greater residual number of ornamented species among species whose mating system is associated with greater skew in male mating success and thus more intense sexual selection. Ornamented species had more subspecies than nonornamented species, even when controlling for geographic range, suggesting an association between subspeciation and ornaments.     

中生代化石森林的高精度重建:方法、进展与展望

木化石对于重建地史时期陆地森林生态系统以及恢复古生态环境和古气候具有重要意义。近20年来,国内外在中生代木化石森林重建的理论创新及实践研究方面已有一系列积累并取得了重要进展,为地史时期古森林群落的重建提供了依据。文中重点介绍高精度化石森林重建的方法,包括野外信息采集、后期数据处理及软件运用等,并基于四川、重庆及新疆等地侏罗系中保存完好的木化石,开展高精度化石森林重建,揭示和重建侏罗纪不同时期森林植被的总体面貌,进而推断和探究古气候变化以及古生态和古地理环境。