GSTDTAP

浏览/检索结果: 共49条,第1-10条 帮助

已选(0)清除 条数/页:   排序方式:
巴美研究指出气候变化将重塑新热带地区蛙类多样性格局 快报文章
气候变化快报,2025年第9期
作者:  董利苹 杜海霞
Microsoft Word(17Kb)  |  收藏  |  浏览/下载:425/0  |  提交时间:2025/04/30
Climate Change  Shrink  Neotropical Frogs  Phylogenetic Endemism  
A giant soft-shelled egg from the Late Cretaceous of Antarctica 期刊论文
NATURE, 2020
作者:  Lewnard, Joseph A.;  Lo, Nathan C.;  Arinaminpathy, Nimalan;  Frost, Isabel;  Laxminarayan, Ramanan
收藏  |  浏览/下载:47/0  |  提交时间:2020/06/22

Egg size and structure reflect important constraints on the reproductive and life-history characteristics of vertebrates(1). More than two-thirds of all extant amniotes lay eggs(2). During the Mesozoic era (around 250 million to 65 million years ago), body sizes reached extremes  nevertheless, the largest known egg belongs to the only recently extinct elephant bird(3), which was roughly 66 million years younger than the last nonavian dinosaurs and giant marine reptiles. Here we report a new type of egg discovered in nearshore marine deposits from the Late Cretaceous period (roughly 68 million years ago) of Antarctica. It exceeds all nonavian dinosaur eggs in volume and differs from them in structure. Although the elephant bird egg is slightly larger, its eggshell is roughly five times thicker and shows a substantial prismatic layer and complex pore structure(4). By contrast, the new fossil, visibly collapsed and folded, presents a thin eggshell with a layered structure that lacks a prismatic layer and distinct pores, and is similar to that of most extant lizards and snakes (Lepidosauria)(5). The identity of the animal that laid the egg is unknown, but these preserved morphologies are consistent with the skeletal remains of mosasaurs (large marine lepidosaurs) found nearby. They are not consistent with described morphologies of dinosaur eggs of a similar size class. Phylogenetic analyses of traits for 259 lepidosaur species plus outgroups suggest that the egg belonged to an individual that was at least 7 metres long, hypothesized to be a giant marine reptile, all clades of which have previously been proposed to show live birth(6). Such a large egg with a relatively thin eggshell may reflect derived constraints associated with body shape, reproductive investment linked with gigantism, and lepidosaurian viviparity, in which a '  vestigial'  egg is laid and hatches immediately(7).


A fossil egg unearthed from Cretaceous deposits in Antarctica is more than 20 cm long, exceeds all known nonavian eggs in volume, is soft-shelled, and was perhaps laid by a giant marine lizard such as a mosasaur.


  
The water lily genome and the early evolution of flowering plants 期刊论文
NATURE, 2020, 577 (7788) : 79-+
作者:  Zhang, Liangsheng;  Chen, Fei;  Zhang, Xingtan;  Li, Zhen;  Zhao, Yiyong;  Lohaus, Rolf;  Chang, Xiaojun;  Dong, Wei;  Ho, Simon Y. W.;  Liu, Xing;  Song, Aixia;  Chen, Junhao;  Guo, Wenlei;  Wang, Zhengjia;  Zhuang, Yingyu;  Wang, Haifeng;  Chen, Xuequn;  Hu, Juan;  Liu, Yanhui;  Qin, Yuan;  Wang, Kai;  Dong, Shanshan;  Liu, Yang;  Zhang, Shouzhou;  Yu, Xianxian;  Wu, Qian;  Wang, Liangsheng;  Yan, Xueqing;  Jiao, Yuannian;  Kong, Hongzhi;  Zhou, Xiaofan;  Yu, Cuiwei;  Chen, Yuchu;  Li, Fan;  Wang, Jihua;  Chen, Wei;  Chen, Xinlu;  Jia, Qidong;  Zhang, Chi;  Jiang, Yifan;  Zhang, Wanbo;  Liu, Guanhua;  Fu, Jianyu;  Chen, Feng;  Ma, Hong;  Van de Peer, Yves;  Tang, Haibao
收藏  |  浏览/下载:75/0  |  提交时间:2020/07/03

Water lilies belong to the angiosperm order Nymphaeales. Amborellales, Nymphaeales and Austrobaileyales together form the so-called ANA-grade of angiosperms, which are extant representatives of lineages that diverged the earliest from the lineage leading to the extant mesangiosperms(1-3). Here we report the 409-megabase genome sequence of the blue-petal water lily (Nymphaea colorata). Our phylogenomic analyses support Amborellales and Nymphaeales as successive sister lineages to all other extant angiosperms. The N. colorata genome and 19 other water lily transcriptomes reveal a Nymphaealean whole-genome duplication event, which is shared by Nymphaeaceae and possibly Cabombaceae. Among the genes retained from this whole-genome duplication are homologues of genes that regulate flowering transition and flower development. The broad expression of homologues of floral ABCE genes in N. colorata might support a similarly broadly active ancestral ABCE model of floral organ determination in early angiosperms. Water lilies have evolved attractive floral scents and colours, which are features shared with mesangiosperms, and we identified their putative biosynthetic genes in N. colorata. The chemical compounds and biosynthetic genes behind floral scents suggest that they have evolved in parallel to those in mesangiosperms. Because of its unique phylogenetic position, the N. colorata genome sheds light on the early evolution of angiosperms.


  
Skeleton of a Cretaceous mammal from Madagascar reflects long-term insularity 期刊论文
NATURE, 2020
作者:  Petit, L.;  Eenink, H. G. J.;  Russ, M.;  Lawrie, W. I. L.;  Hendrickx, N. W.;  Philips, S. G. J.;  Clarke, J. S.;  Vandersypen, L. M. K.;  Veldhorst, M.
收藏  |  浏览/下载:33/0  |  提交时间:2020/05/13

The fossil record of mammaliaforms (mammals and their closest relatives) of the Mesozoic era from the southern supercontinent Gondwana is far less extensive than that from its northern counterpart, Laurasia(1,2). Among Mesozoic mammaliaforms, Gondwanatheria is one of the most poorly known clades, previously represented by only a single cranium and isolated jaws and teeth(1-5). As a result, the anatomy, palaeobiology and phylogenetic relationships of gondwanatherians remain unclear. Here we report the discovery of an articulated and very well-preserved skeleton of a gondwanatherian of the latest age (72.1-66 million years ago) of the Cretaceous period from Madagascar that we assign to a new genus and species, Adalatherium hui. To our knowledge, the specimen is the most complete skeleton of a Gondwanan Mesozoic mammaliaform that has been found, and includes the only postcranial material and ascending ramus of the dentary known for any gondwanatherian. A phylogenetic analysis including the new taxon recovers Gondwanatheria as the sister group to Multituberculata. The skeleton, which represents one of the largest of the Gondwanan Mesozoic mammaliaforms, is particularly notable for exhibiting many unique features in combination with features that are convergent on those of therian mammals. This uniqueness is consistent with a lineage history for A. hui of isolation on Madagascar for more than 20 million years.


Adalatherium hui, a newly discovered gondwanatherian mammal from Madagascar dated to near the end of the Cretaceous period, shows features consistent with a long evolutionary trajectory of isolation in an insular environment.


  
Extant timetrees are consistent with a myriad of diversification histories 期刊论文
NATURE, 2020, 580 (7804) : 502-+
作者:  Bhaskar, M. K.;  Riedinger, R.;  Machielse, B.;  Levonian, D. S.;  Nguyen, C. T.;  Knall, E. N.;  Park, H.;  Englund, D.;  Loncar, M.;  Sukachev, D. D.;  Lukin, M. D.
收藏  |  浏览/下载:58/0  |  提交时间:2020/07/03

An infinite number of alternative diversification scenarios-which may have markedly different, but equally plausible, dynamics-can underpin a given time-calibrated phylogeny of extant species, suggesting many previous studies have over-interpreted phylogenetic evidence.


Time-calibrated phylogenies of extant species (referred to here as '  extant timetrees'  ) are widely used for estimating diversification dynamics(1). However, there has been considerable debate surrounding the reliability of these inferences(2-5) and, to date, this critical question remains unresolved. Here we clarify the precise information that can be extracted from extant timetrees under the generalized birth-death model, which underlies most existing methods of estimation. We prove that, for any diversification scenario, there exists an infinite number of alternative diversification scenarios that are equally likely to have generated any given extant timetree. These '  congruent'  scenarios cannot possibly be distinguished using extant timetrees alone, even in the presence of infinite data. Importantly, congruent diversification scenarios can exhibit markedly different and yet similarly plausible dynamics, which suggests that many previous studies may have over-interpreted phylogenetic evidence. We introduce identifiable and easily interpretable variables that contain all available information about past diversification dynamics, and demonstrate that these can be estimated from extant timetrees. We suggest that measuring and modelling these identifiable variables offers a more robust way to study historical diversification dynamics. Our findings also make it clear that palaeontological data will continue to be crucial for answering some macroevolutionary questions.


  
Late Cretaceous neornithine from Europe illuminates the origins of crown birds 期刊论文
NATURE, 2020, 579 (7799) : 397-+
作者:  Shao, Zhengping;  Flynn, Ryan A.;  Crowe, Jennifer L.;  Zhu, Yimeng;  Liang, Jialiang;  Jiang, Wenxia;  Aryan, Fardin;  Aoude, Patrick;  Bertozzi, Carolyn R.;  Estes, Verna M.;  Lee, Brian J.;  Bhagat, Govind;  Zha, Shan;  Calo, Eliezer
收藏  |  浏览/下载:68/0  |  提交时间:2020/05/13

Our understanding of the earliest stages of crown bird evolution is hindered by an exceedingly sparse avian fossil record from the Mesozoic era. The most ancient phylogenetic divergences among crown birds are known to have occurred in the Cretaceous period(1-3), but stem-lineage representatives of the deepest subclades of crown birds-Palaeognathae (ostriches and kin), Galloanserae (landfowl and waterfowl) and Neoaves (all other extant birds)-are unknown from the Mesozoic era. As a result, key questions related to the ecology(4,5), biogeography(3,6,7) and divergence times(1,8-10) of ancestral crown birds remain unanswered. Here we report a new Mesozoic fossil that occupies a position close to the last common ancestor of Galloanserae and fills a key phylogenetic gap in the early evolutionary history of crown birds(10,11). Asteriornis maastrichtensis, gen. et sp. nov., from the Maastrichtian age of Belgium (66.8-66.7 million years ago), is represented by a nearly complete, three-dimensionally preserved skull and associated postcranial elements. The fossil represents one of the only well-supported crown birds from the Mesozoic era(12), and is the first Mesozoic crown bird with well-represented cranial remains. Asteriornis maastrichtensis exhibits a previously undocumented combination of galliform (landfowl)-like and anseriform (waterfowl)-like features, and its presence alongside a previously reported Ichthyornis-like taxon from the same locality(13) provides direct evidence of the co-occurrence of crown birds and avialan stem birds. Its occurrence in the Northern Hemisphere challenges biogeographical hypotheses of a Gondwanan origin of crown birds(3), and its relatively small size and possible littoral ecology may corroborate proposed ecological filters(4,5,9) that influenced the persistence of crown birds through the end-Cretaceous mass extinction.


A newly discovered fossil from the Cretaceous of Belgium is the oldest modern bird ever found, showing a unique combination of features and suggesting attributes shared by avian survivors of the end-Cretaceous extinction.


  
The dental proteome of Homo antecessor 期刊论文
NATURE, 2020, 580 (7802) : 235-+
作者:  Abram, Nerilie J.;  Wright, Nicky M.;  Ellis, Bethany;  Dixon, Bronwyn C.;  Wurtzel, Jennifer B.;  England, Matthew H.;  Ummenhofer, Caroline C.;  Philibosian, Belle;  Cahyarini, Sri Yudawati;  Yu, Tsai-Luen;  Shen, Chuan-Chou;  Cheng, Hai;  Edwards, R. Lawrence;  Heslop, David
收藏  |  浏览/下载:63/0  |  提交时间:2020/07/03

Analyses of the proteomes of dental enamel from Homo antecessor and Homo erectus demonstrate that the Early Pleistocene H. antecessor is a close sister lineage of later Homo sapiens, Neanderthal and Denisovan populations in Eurasia.


The phylogenetic relationships between hominins of the Early Pleistocene epoch in Eurasia, such as Homo antecessor, and hominins that appear later in the fossil record during the Middle Pleistocene epoch, such as Homo sapiens, are highly debated(1-5). For the oldest remains, the molecular study of these relationships is hindered by the degradation of ancient DNA. However, recent research has demonstrated that the analysis of ancient proteins can address this challenge(6-8). Here we present the dental enamel proteomes of H. antecessor from Atapuerca (Spain)(9,10) and Homo erectus from Dmanisi (Georgia)(1), two key fossil assemblages that have a central role in models of Pleistocene hominin morphology, dispersal and divergence. We provide evidence that H. antecessor is a close sister lineage to subsequent Middle and Late Pleistocene hominins, including modern humans, Neanderthals and Denisovans. This placement implies that the modern-like face of H. antecessor-that is, similar to that of modern humans-may have a considerably deep ancestry in the genus Homo, and that the cranial morphology of Neanderthals represents a derived form. By recovering AMELY-specific peptide sequences, we also conclude that the H. antecessor molar fragment from Atapuerca that we analysed belonged to a male individual. Finally, these H. antecessor and H. erectus fossils preserve evidence of enamel proteome phosphorylation and proteolytic digestion that occurred in vivo during tooth formation. Our results provide important insights into the evolutionary relationships between H. antecessor and other hominin groups, and pave the way for future studies using enamel proteomes to investigate hominin biology across the existence of the genus Homo.


  
Climate and plant community diversity in space and time 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (9) : 4464-4470
作者:  Harrison, Susan;  Spasojevic, Marko J.;  Li, Daijiang
收藏  |  浏览/下载:38/0  |  提交时间:2020/05/13
aridification  climate change  drought  functional diversity  phylogenetic diversity  
A simple dynamic model explains the diversity of island birds worldwide 期刊论文
NATURE, 2020
作者:  Li, Junxue;  Wilson, C. Blake;  Cheng, Ran;  Lohmann, Mark;  Kavand, Marzieh;  Yuan, Wei;  Aldosary, Mohammed;  Agladze, Nikolay;  Wei, Peng;  Sherwin, Mark S.;  Shi, Jing
收藏  |  浏览/下载:51/0  |  提交时间:2020/07/03

Colonization, speciation and extinction are dynamic processes that influence global patterns of species richness(1-6). Island biogeography theory predicts that the contribution of these processes to the accumulation of species diversity depends on the area and isolation of the island(7,8). Notably, there has been no robust global test of this prediction for islands where speciation cannot be ignored(9), because neither the appropriate data nor the analytical tools have been available. Here we address both deficiencies to reveal, for island birds, the empirical shape of the general relationships that determine how colonization, extinction and speciation rates co-vary with the area and isolation of islands. We compiled a global molecular phylogenetic dataset of birds on islands, based on the terrestrial avifaunas of 41 oceanic archipelagos worldwide (including 596 avian taxa), and applied a new analysis method to estimate the sensitivity of island-specific rates of colonization, speciation and extinction to island features (area and isolation). Our model predicts-with high explanatory power-several global relationships. We found a decline in colonization with isolation, a decline in extinction with area and an increase in speciation with area and isolation. Combining the theoretical foundations of island biogeography(7,8) with the temporal information contained in molecular phylogenies(10) proves a powerful approach to reveal the fundamental relationships that govern variation in biodiversity across the planet.


Using a global molecular phylogenetic dataset of birds on islands, the sensitivity of island-specific rates of colonization, speciation and extinction to island features (area and isolation) is estimated.


  
A new coronavirus associated with human respiratory disease in China 期刊论文
NATURE, 2020, 579 (7798) : 265-+
作者:  Rollie, Clare;  Chevallereau, Anne;  Watson, Bridget N. J.;  Chyou, Te-yuan;  Fradet, Olivier;  McLeod, Isobel;  Fineran, Peter C.;  Brown, Chris M.;  Gandon, Sylvain;  Westra, Edze R.
收藏  |  浏览/下载:104/0  |  提交时间:2020/07/03

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health(1-3). Despite intense research efforts, how, when and where new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing(4) of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here '  WH-Human 1'  coronavirus (and has also been referred to as '  2019-nCoV'  ). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China(5). This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.