THE PHYLOGENETIC RELATIONSHIPS AND BIOGEOGRAPHY OF TRUE PORPOISES (MAMMALIA: PHOCOENIDAE) BASED ON MORPHOLOGICAL DATA

Prior studies of phylogenetic relationships among phocoenids based on morphology and molecular sequence data conflict and yield unresolved relationships among species. This study evaluates a comprehensive set of cranial, postcranial, and soft anatomical characters to infer interrelationships among extant species and several well-known fossil phocoenids, using two different methods to analyze polymorphic data: polymorphic coding and frequency step matrix. Our phylogenetic results confirmed phocoenid monophyly. The division of Phocoenidae into two subfamilies previously proposed was rejected, as well as the alliance of the two extinct genera Salumiphocaena and Piscolithax with Phocoena dioptrica and Phocoenoides dalli . Extinct phocoenids are basal to all extant species. We also examined the origin and distribution of porpoises within the context of this phylogenetic framework. Phocoenid phylogeny together with available geologic evidence suggests that the early history of phocoenids was centered in the North Pacific during the middle Miocene, with subsequent dispersal into the southern hemisphere in the middle Pliocene. A cooling period in the Pleistocene allowed dispersal of the southern ancestor of Phocoena sinus into the North Pacific (Gulf of California).     

小麦的分类、起源与进化

小麦是世界历史上最古老的作物之一,约在一万年以前,在西南亚,人类首先成功地将小麦进行栽培生产粮食,因此小麦栽培历史和人类开化有着密切的相互关系。在现代世界农业中,小麦也是最重要的作物之一。它分布面积很广,从北纬67°的挪威、芬兰和苏联到南纬45°的阿根庭都有栽培。世界生产小麦的地区有苏联南部、美国中部平原和加拿大相邻地区、地中海地区、中国、印度、阿根廷北部和澳大利亚的西南部。这类作物在比较宽的环境 范围内都能获得高产。据统计,全世界有1/3的人口以小麦为主要粮食.消费的小麦食物卡值占全世界的20%以上。     

小麦的分类、起源与进化

小麦是世界历史上最古老的作物之一,约在一万年以前,在西南亚,人类首先成功地将小麦进行栽培生产粮食,因此小麦栽培历史和人类开化有着密切的相互关系。在现代世界农业中,小麦也是最重要的作物之一。它分布面积很广,从北纬67°的挪威、芬兰和苏联到南纬45°的阿根庭都有栽培。世界生产小麦的地区有苏联南部、美国中部平     

麝属（MOSCHUS）的分类

麝属（ＭＯＳＣＨＵＳ）的分类ＣｏｌｉｎＰ．Ｇｒｏｖｅｓ（澳大利亚国立大学史前学和人类学系,堪培拉）王应祥（中国科学院昆明动物研究所,昆明）ＰｅｔｅｒＧｆｕｂｂ（英国伦敦Ｎ１７６ＰＥ,Ｄｏｗｎｈｉｌｌ公园路３５）麝类是古北区的特有类群,它们中的大多数种...     

猪尾鼠的分类,分布与分化

本文对猪尾鼠（Ｔｙｐｈｌｏｍｐｓｃｉｎｅｒｅｕｓ）的亚种分化、分布和亚种间的相互关系作了研究。它被划分为５个亚种．其中,分布于长江流域中上游一带的猪尾鼠为一新亚种（大娄山亚种,Ｔ．ｃ．ｄａｌｏｕｓｈａｎｅｎｓｉｓ）,以脑颅较隆突、眶间较窄、鼻骨后缘止于颌额缝之前为其特征;广西珠江以南的猪尾鼠为另一新亚种（广西亚种,Ｔ．ｃ．ｇｕａｎｇｘｉｅｎｓｉｓ）,以腹面污黄色,脑颅高隆而宽阔为其特征。通过对２２个可数性状和测量性状的聚类分析,结果表明：５个亚种可分为两组,其中,越南北部的沙巴亚种和广西南部的广西亚种为一组,性状相对特化;长江流域的大娄山亚种、云南的景东亚种和华东地区的指名亚种为另一组,性状相对原始。后一亚种组小,大娄山亚种和景东亚种有较多的相似性,关系比较密切,指名亚种保有较多的原始特征。猪尾鼠起源于更新世早期,起源地可能是华南大陆。现今的猪尾鼠在我国长江流域及其以南地区的分布几乎是连续的,向北可分布到秦岭南坡和甘肃南部,向酉到滇中哀牢山。江河的阻隔和地带性环境气候的差异和变化可能是导致猪尾鼠亚种分化的主要原因。     

广西百色和永乐盆地的始新世猪类化石──兼论早期猪类的分类和演化(英文)

描述了广西百色及永乐盆地发现的中始新世最晚期一晚始新世的猪类化石。这批已知最早的猪超科化石,大大丰富了亚洲地区的早期猪类,对了解全球猪类的早期演化有着重要价值。广西的材料被确定为两个新属新种：萨氏始新猪Ｅｏｃｅｎｃｈｏｅｒｕｓ ｓａｖａｇｅｉ和广西华夏猪Ｈｕａｘｉａｃｈｏｅｒｕｓ ｇｕａｎｇｘｉｅｎｓｉｓ,一个新种：粗壮暹罗猪Ｓｉａｍｏｃｈｏｅｒｕｓ　ｖｉｒｉｏｓｕｓ和一个未定属种：Ｔａｙａｓｓｕｉｄａｅ　ｇｅｎ．ｅｔ　ｓｐ．ｉｎｄｅｔ。加上已发表的单尖旅猪Ｏｄｉｏｃｈｏｅｒｕｓ　ｕｎｉｃｏｎｕｓ,百色、永乐盆地共计发现了５种始新世猪类化石。新属Ｅｏｃｅｎｃｈｏｅｒｕｓ虽然臼齿结构简单,与原始的古猪类（ｐａｉａｅｏｃｈｏｅｒｉｄ）接近,但因其Ｍ３具有一个明显的跟座而被归入猪科。早期猪科动物非常原始的臼齿形式证明,猪科动物的起源并不晚于古猪科（Ｐａｌａｅｏｃｈｏｅｒｉｄａｅ）和西科（Ｔａｙａｓｓｕｉｄａｅ）。旧大陆的古猪类长期以来被认为与新大陆的西类（ｔａｙａｓｓｕｉｄ）更为接近,多数学者将其归入西科。笔者认为两者共有的近祖特征,并不能支持它们更近的亲缘关系,而且古猪类缺乏典型西类的近裔特征,因而支持将Ｐａｌａ?     

进化论与分类学

达尔文在《物种起源》的最后结语中指出: “我们的分类将成为——尽可能地使之成为——生物的系谱,那时将真的显示出所谓‘创造的计划’了。当分类学有了确定目的之时,它的法则将趋于简单。我们没有宗谱或纹章,我们必须用长期遗传下来的各种性状,去发现和探索自然系谱上的许多分歧的系线”。     

生态变异在植物分类学和进化中的重要性

生物群体的变异性是有机体所有类群的一个属性。在本世纪的二十年代至四十年代,植物进化研究的一个重要的目的是了解种内和群体内存在的复杂的变异式样。近一、二十年来,进化生物学研究工作的一个重要的方面已转移到生态因素对个体、群体和种在环境和生物两方面的效应以及这些效应在生态学、分类学和进化中实际的含义上来。种内变异的描述和分类已成为当前最有挑战性的问题和最值得探索的领域之一。可塑性和耐受性在有花植物中普遍存在。但对大多数种来说,可塑性是有限的:一个具有较大分布区的种的不同地区的群体往往具有不同的基因型,而这些基因型是遗传和生态两个因素之间长时期复杂的相互作用的产物。种内变异是生态型性质还是梯度变异性质取决于自然界不同气候带或气候条件之间是急剧过渡还是逐渐过渡。但土壤和生物因素有时也参与宗的分化。群体和种内的变异不一定都有外部形态的变化,而是在多数情况下表现为生理和生化的差异。适应于富含铝、铜或锌等重金属盐的土壤的小地理宗是由足够强大的歧化选择而不是由内在的隔离机制来维持。多态现象,即群体内不同遗传变异体的频率变化,可能与自然选择有关。现有的主要种下分类等级——亚种、变种和变型,不仅不能满足描述种内生态多样性和复杂的变异式样的     

大熊猫颅内腔的演化(英文)

描述比较了早更新世大熊猫小种(Ailuropoda microta)、晚更新世大熊猫巴氏种(A baconi)、现生大熊猫(A.melanoleuca)和北极熊(Ursus maritimus)的虚拟三维颅内模。大熊猫脑窝内模的形态在小种、巴氏种和现生种之间大致相似,而与北极熊区分明显。大熊猫的脑窝内模容积从小种到巴氏种呈增大趋势,但从巴氏种到现生种呈减小趋势。大熊猫的大脑沟回在脑窝内模上留下的印痕非常明显,并从小种经巴氏种到现生种则呈稳定增长趋势。相反,北极熊的大脑沟回在脑窝内模上留下的印痕不明显,而血管印痕在脑窝枕区的两侧很明显。嗅球窝内模腹部的纵沟在大熊猫小种发育,在巴氏种较弱,在大熊猫现生种几乎不存在,而在北极熊较发育。大熊猫的脑量商在小种、巴氏种和现生种之间差别不大,但大熊猫的脑量商明显大于北极熊。大熊猫的副鼻窦在小种、巴氏种和现生种之间的差别不大,但与北极熊差别较大。大熊猫的额窦很长、较高、背侧脊形,而北极熊的额窦长度相对较短、高度较低、宽度稍大、背侧平缓。大熊猫的上颌窦较宽,而北极熊的则较窄。大熊猫的蝶窦很小,而北极熊的则较大,覆盖在脑腔前侧。大熊猫这3个不同时期的种与北极熊在颅内腔上这些明显的差异支持将大熊猫从熊科中独立出来的分类。     

A SPALACOLESTINE SPALACOTHERIID (MAMMALIA,TRECHNOTHERIA) FROM THE EARLY CRETACEOUS (BARREMIAN) OF SOUTHERN ENGLAND AND ITS BEARING ON SPALACOTHERIID EVOLUTION

Abstract: Bulk screening of Early Cretaceous (Barremian) Wealden Group strata of the Wessex Formation exposed on the south‐west and south‐east coasts of the Isle of Wight, southern England, has resulted in the recovery of fragmentary remains pertaining to a new spalacolestine spalacotheriid mammal, Yaverlestes gassoni gen. et sp. nov. These represent the first European record of the Spalacolestinae. The remains comprise a dentulous incomplete dentary and isolated upper and lower molariforms, the former representing the most substantial mammal remains yet recovered from the Wealden Group. Hitherto, six species of spalacotheriid mammal were known from the Lower Cretaceous of Europe. All are referred to the genus Spalacotherium but in the case of taxa diagnosed on the basis of isolated lower teeth and other specimens where the post‐canine dentition is incompletely known, it is now evident that these referrals should be treated with caution. Furthermore, the new Wessex Formation spalacotheriid and recently described spalacotheriids from the ?Barremian of Japan, and the Barremian and Aptian of China exhibit combinations of characters that suggest that spalacotheriids were more diverse and that their evolution was more complex than previously recognized. The systematic position of an isolated tooth from the basal Cretaceous Lourinhã Formation of Portugal is discussed and the tooth reassigned to the Spalacotheriidae. Together with the new Wessex Formation taxon, eight species are now known from the Lower Cretaceous of Europe. The discovery of a spalacolestine in the Barremian Wessex Formation supports the concept of faunal interchange between Europe, Asia and North America during the Early Cretaceous. It also supports derivation of North American spalacotheriids from a European or Eurasian ancestor.     

应用同工酶进行宽皮柑桔分类及其进化研究

利用聚丙烯酰胺凝胶电泳法,分析了50个宽皮柑桔生物型及5个甜橙品种的过氧化物酶、谷氨酸草酰乙酸转氨酶、四唑氧化酶、6-磷酸葡萄糖异构酶、6-磷酸葡萄糖变位酶、超氧化物歧化酶、苹果酸酶以及酯酶等8种酶系统同工酶。运用数量分类学的原理及方法,对同工酶资料进行了聚类分析。结果表明,宽皮柑桔的起源是多元的,小果类桔属于宽皮柑桔的原始类型,在进化过程中起着较为重要的作用。中国原产宽皮柑桔的代表种以道县野桔、马鼻桔或狗屎柑为佳。柑的来源有两条途径,即桔橙杂种和桔的单元演化;蕉柑是栟柑与甜橙的杂种;温州蜜柑来源于黄岩本地广桔的实生变异。     

菱臼齿兽((犭亚)目、哺乳纲)耳区的骨骼结构

本文详细描述了菱臼齿兽耳区各个部分的基本结构;并指出了耳区结构与某些啮齿类的相似性,以及中耳鼓泡组成成份与戈壁(犭亚)兽(Anagale gobiensis)的区别。     

刚毛蚜族系统分类及分布格局(半翅目,毛管蚜科)

系统研究了刚毛蚜族Schoutedeniini的分类,世界已知3属7种;重新定义了该族的鉴别特征,编制了分属、分种检索表,补充了已知种的地理分布与寄主植物信息;记述了1中国新纪录种--酸果藤刚毛蚜Schoutedenia emblica(Patel et Kulkarni,1953)的形态特征,提供了形态特征图和照片.刚毛蚜族的现生分布格局呈明显的冈瓦那古陆分布,马达加斯加岛及青藏高原东南缘为其物种分化中心,文章简单探讨了该族现代分布格局的可能成因.     

EVOLUTION OF BREEDING DISTRIBUTIONS IN THE OLD WORLD LEAF WARBLERS (GENUS PHYLLOSCOPUS)

Among Palearctic warblers of the genus Phylloscopus those species that breed farther north occupy larger geographical ranges than those which breed farther south (Rapoport's rule). We suggest that much of this pattern is a consequence of the differential ability of species to occupy areas rendered inhospitable during the Pleistocene. In support of this suggestion, the midpoint of breeding range in a north-south direction has been an exceptionally labile trait through evolutionary time. Comparisons of ecological attributes of those species breeding in the Himalayas with close relatives in Siberia implies a role for habitat tracking in determining which species have been able to colonize northern areas; hypotheses based on climate and climatic variability have less support. In addition there is a likely role for geographic barriers and/or biotic interactions in preventing some taxa from spreading from small southern ranges.     

我国更新世两属鬣狗(Hyaena,Crocuta)的关系与分类

多数学者认为,更新世的两属鬣狗与现生两属鬣狗相比,化石Hyaena不同于现生Hya-ena,而与Crocuta更为相近。本文结合近年来采集的新材料的研究,进一步论证了化石Hya-ena与Crocuta的密切关系,并且赞成把我国的Hyaena licenti和H.sinensis的属名订正为Pachycrocuta。     

EXTERNAL MORPHOLOGY AND PIGMENTATION OF THE VAQUITA, PHOCOENA SINUS (CETACEA: MAMMALIA)

The vaquita, Phocoena sinus , is a porpoise in the family Phocoenidae that lives only in the Gulf of California. The external appearance of P. sinus was unknown until 13 fresh specimens were recently examined. The most obvious morphological feature distinguishing P. sinus from its two congeners is the proportionately higher dorsal fin. The most striking features of the pigmentation pattern are the large black eye patches and the black upper and lower lip patches. In both areas, the pigmentation contrasts sharply with the surrounding light gray coloration. The total lengths of the specimens ranged from 70.3 cm (a neonate) to 143.5 cm (an adult female).