做一个会讲故事的科学家:读《十年山野路漫漫——新生代化石考察记》

《十年山野路漫漫——新生代化石考察记》是一部古生物科学工作者的野外科考笔记。作者用朴实而流畅的文笔,记录了十年来在野外开展古生物学考察研究和在国外参加学术活动的经历。十年间,从青藏高原到江南水乡,从泰国呵叻的热带雨林到中国东北的林海雪原,从南美的安第斯山到欧洲的西西里;从美国的内华达、南欧的巴尔干到新疆的喀什和塔什库尔干.

盘点云南植物王国的家底

云南是中国生物多样性最丰富的省份,在不到全国国土面积4.1%的区域内分布了苔藓126科499属1906种、蕨类61科193属1363种、裸子植物9科25属113种、被子植物244科2367属15951种,即云南高等植物的种数为19333种,占全国高等植物种数的一半以上。除了高等植物,云南另有地衣66科203属1067种、大型真菌124科599属2729种。云南具有从热带雨林到高山流石滩灌丛的各种植被类型,共包含14个植被型、38个植被亚型、474个群系。丰富的地球环境多样性、立体气候和特殊的地理位置是云南植物多样性丰富的原因。近年来,云南开展了一系列的保护行动,如:摸清植物的家底、编制保护名录、建立种质资源库、保护极小种群等,使云南的植物多样性得到了有效的保护。

A New Species of Tsuga(Pinaceae) based on Lignified Wood from the Late Miocene of Central Yunnan, China, and Its Paleoenvironmental Implications

A new species, Tsuga nanfengensis sp.nov.（Pinaceae）, is described on the basis of lignified fossil wood from the late Miocene of the Xianfeng Basin, central Yunnan, southwestern China.Detailed observation of the fossil wood specimens show the following characteristics： distinct growth rings, absence of resin canals, uniseriate bordered pits in the radial wall of tracheids, ray tracheids and piceoid and cupressoid cross-field pits.These features indicate similarities to the wood of extant Tsuga canadensis, T.chinensis, and T.dumosa.According to the fossil record, Tsuga was present in Xundian County during the Miocene.Today Tsuga is drought intolerant, preferring wet conditions with no extant species growing naturally in Xundian County.The presence of Tsuga in the Miocene of Xundian County indicates a humid climate consistent with previous palaeoclimatic reconstructions showing a wetter and probably shorter dry season in the Miocene, relative to the present day.Therefore, the change in the local climate such as increasing aridity through the Miocene might explain the local extinction of Tsuga from central Yunnan.

Fossils of Quercus sect. Heterobalanus can help explain the uplift of the Himalayas

Using data from previous research on Quercus sect. Heterobalanus, the coexistence approach to Xix-abangma and Namling fossil sets, and altitudinal ranges of vegetation presented by fossil floras, a re-view and reevaluation have been made of existing theories on the uplift of the Himalayas, especially the palaeoaltitudes of Xixabangma and Namling in Tibet. The Xixabangma fossil set has a palaeoaltitude range of 2500―3500 m, and has risen 2200―3400 m since the Pliocene. The lower and upper assem-blages of the Miocene Namling had palaeoaltitudes of 2500―3000 m and 2800―3000 m, respectively. Therefore, Namling has risen at least 1300 m since the Miocene, thereby challenging some existing theories that suggest Namling has been static since the Miocene.

Land bridge and long-distance dispersal——Old views, new evidence

The study of land bridge based on con- tinental drift1) and long-distance dispersal are gaining increasing attention in biogeography. We review several major dispersal theories including the Mal- pigiacea route, patterns of chameleon dispersal and the floating island model. The Malpigiaceae route indicates that the Malpigiaceae family originated in northern South America and that members of several clades migrated into North America and subsequently moved via north Atlantic land connections into the Old World starting in the Eocene. This route may also explain many other pantropic disjunction patterns, including some Chinese plants disjunctions, involving South America. Not all biogeographical distribution patterns can be explained by vicariance theory, so more research, including chameleon distribution, has recently focused on long-distance dispersal. The lat- est analyses suggest that chameleons have dis- persed over long-distances from Madagascar on several occasions. The floating island model would explain flora and fauna similarities between South America and Africa. Studying long-distance dispersal mechanisms is important for understanding distribu- tion patterns and even the spread of pandemics. More research on the specific implications of long- distance dispersal for biogeography is necessary.

Origin and differentiation of endemism in the flora of China

The present paper analyzed 239 endemic genera in 67 families in the flora of seed plants in China.The results showed that there are five families containing more than ten endemic genera,namely,Gesneriaceae(27),which hereafter refers to the number of endemic genera in China,Composite(20),Labiatae(12),Cruciferae(11),and Umbelliferae(10),15 families with two endemic genera,and another 30 families with only one endemic genus.Four monotypic families(Ginkgoaceae,Davidiaceae,Eucommiaceae and Acanthochlamydaceae)are the most ancient,relict and characteristic in the flora of seed plants in China.Based on integrative data of systematics,fossil history,and morphological and molecular evidence of these genera,their origin,evolution and relationships were discussed.In gymnosperms,all endemic genera are relicts of the Arctic-Tertiary flora,having earlier evolutionary history,and can be traced back to the Cretaceous or to the Jurassic and even earlier.In angiosperms,the endemic genera are mostly relicts,and are represented in all lineages in the“Eight-Class System of Classification of Angiosperms”,and endemism can be found in almost every evolutionary stage of extant angiosperms.The relict genera once occupied huge areas in the northern hemisphere in the Tertiary or the late Cretaceous,while neo-endemism mostly originated in the late Tertiary.They came from Arctic-Tertiary,Paleo-tropical-Tertiary and Tethys-Tertiary florisitic elements,and the blend of the three elements with many genera of autochthonous origin.The endemism was formed when some dispersal routes such as the North Atlantic Land Bridge,and the Bering Bridge became discontinuous during the Tertiary,as well as the climate change and glaciations in the late Tertiary and the Quaternary.Therefore,the late Tertiary is the starting point of extant endemism of the flora in China.

肩袖脂肪浸润的研究进展

肩袖损伤(rotator cuff tear,RCT)在肌骨系统中发病率仅次于腰背部疼痛,是患者因肩部不适就诊的最常见疾病,严重影响患者的生活质量^([1])。RCT在60-70岁人群中发病率约30%,并随年龄增长而逐渐增加^([2])。