Origin of Birds: Decade-Long Efforts and Evidence from China

<正>In its 2014 version of top 10 ground-breaking discoveries and achievements released on December 19,Science,the world-leading journal included the transition from dinosaurs to birds in its annual selection,noting that a series of papers detailed how certain dinosaurian lineages developed small,lightweight body features,which have enabled them to evolve into birds and gain the ability to fly.The dinosaur-bird transition,now evaluated as one of     

A New "Missing Link" in Dinosaur's Evolution Found

A group of paleontologists from China, the United States and Canada have made new progress in tracking down the process of the evolution of smallsized dinosaurs and the origin of birds through intensive analysis of the fossils of a newly found dinosaur,Sinovenator, a close relative of birds. In a letter published in the Feb.14 issue of Nature, dinosaur expert Dr. Xu Xing at CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) and his coworkers reveal some interesting phenomena in the process of the evolution of dinosaurs towards birds.     

Unlike birds,bats might use a different magnetic compass to navigate

Bats, the only mammals known to possess the real ability to fly, have fascinated zoologists for a long time with their long-distance migration. How do they find their way home from an altitude of kilometers above sea level, where their stunt of ultrasonic echolocation does not work？ Recent discoveries supported the theory that bats might be able to use magnetic clues to figure out their own position,just like what birds do. However, the latest results from a joint study by a group of researchers from the CAS, East China Normal University and University of Auckland reveal that bats apply an interesting strategy different from the one underlying birds＇ orientation technique, though they both are believed to derive information about their position from the subtle changes in the magnetic field of the Earth.     

New Finding on Origin of Avian Predentary in Mesozoic Birds

<正>The predentary bone is one of the most enigmatic skeletal elements in avian evolution. Located at the tip of the lower jaw, this bone is absent in more primitive birds and in living birds; it is thought to have been lost during evolution. For over 30 years the origin and function of the avian predentary has remained mysterious. Now, however, Alida Bailleul, LI Zhiheng, Jingmai O'Connor and ZHOU Zhonghe from the Institute of     

Delayed Antarctic melt season reduces albedo feedback

Antarctica’ s response to climate change varies greatly both spatially and temporally.Surface melting impacts mass balance and also lowers surface albedo.We use a 43-year record(from 1978 to 2020) of Antarctic snow melt seasons from space-borne microwave radiometers with a machine-learning algorithm to show that both the onset and the end of the melt season are being delayed.Granger-causality analysis shows that melt end is delayed due to increased heat flux from the ocean to the atmosphere at m...     

Climate Change and its Impact on Water Resources in the Huai River Basin

Rainfall and air temperature data from six meteorological stations above the Bengbu Sluice and hydrological and water resources evaluation data from the Bengbu Hydrological Station in the Huai River Basin from 1961 to 2008 are used to analyze the impact of changes in climatic factors on the amount of water resources in the Basin. There was a general trend of rise in its average annual air temperature, with the highest increase of 0.289oC/10a recorded at Bengbu in Anhui Province. Rising rainfall was mainly observed in the western part of the study area, while rainfall actually declined in the eastern part, i.e. the middle reaches of the Huai River. The Average rainfall in the study area was in a vaguely declining trend. In other words, the rainfall in the Basin is still much affected by natural fluctuations. On the whole, there was a trend of gradual decrease in the quantity of the Basin’s water resources for the period under study. Water resources quantity is found to fall with decreasing rainfall and rising air temperature. Regression analysis is used to establish a mathematical model between water resources quantity and climatic factors (i.e. air temperature and rainfall) in order to explore the impact of climate change on water resources in the Basin. Moreover, various scenarios are set to quantitatively analyze the response of water resources to climate change. Sensitivity analysis shows that changes in rainfall have a much bigger impact on its water resources quantity than changes in its air temperature.     

Dinosaurs of a Feather

<正>From the earliest days of paleontological research, the origin of birds was an area of special interest. Largely thanks to the work of Thomas Huxley and the     

鳞毛蕨属的生物系统学研究

At the outset the paper begins with a brief discussion of the geographical origin of the genus Dryopteris. With the cytological data so far available the author presumed that the No- rthern Hemisphere and possibly Eurasia is the geographical origin of the genus and that the Eastern Himalayas, China and Japan is the centre of speciation of the genus, and thence has spread to other continents along several routes. He is also of the opinion that the genus  tends to evolve the highest grade of polyploidy where it has existed longest. On the other hand, he pointed out that the production of polyploids may occur most frequently in response to pressures which a group meets in the course of its migration in space and time, with  the  majority  of diploids persisting as relics close to the original centre of diversification.       He then described the progress of the biosystematics of the European and North American Dryopteris, which has been undertaken through a close cooperation among botanists, cytologists and phytochemists of different nations. This team is also looking forward to a cooperation with the Chinese botanists in the study of East Asian species of Dryopteris, so that the relationships of Chinese species and those of other floras can be understood.       The term biosystematics had been invented to mean experimental studies of breeding sy- stems of the species concerned in order to ellucidate their evolutionary relationships.  It stems from the early researches of Professor Irene Manton whose classical book “Problems of Cytology and Evolution in the Pteridophyta” (1950) laid the foundation of Biosystematics. Manton was also the first to introduce the acetocarmine squash  method for staining  chromosomes  in  the spore-mother-cells at meiosis.       The lecture was illustrated with diagrams showing in detail the pairing behaviour of the chromosomes at the metaphase in meiosis and the formation of the polyploidies of different levels.       Besides cytological approach two other techniques have been also applied to the systematic studies of Dryopteris. The first is the comparison of sporoderms  using the scaning  electron microscope, revealing different ornamentations on the pericine. The second is the study of plant chemistry, in particular, that of the phloroglucinoles by thinlayer chromatography.       The remaining far greater part of the paper is devoted to analysing cytologically the Eu- ropean and North American species of Dryopteris in three groups, showing the lines of experi-mental work that has resulted in the understanding of their evolutional relationships.     

Root Chemicals Help Plants Shaping Soil Microbes

<正>Plants, though passive and still as it appears, are considered to be quite active to engage with other living things, particularly in the root part that faces relatively more complicated surroundings. In a recent report in Science, researchers from the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences and their cooperators from the John Innes Center, UK unraveled new evidence that plants can     

China starts largest ever paleoanthropology project

China is believed to be a country especially endowed with the fossils and materials related to early human evolution, next only to the African continent in terms of fecundity and systematism. These materials, including physical and cultural remains of huminids, their associated fauna and flora as well as prehistoric sites, are essential for probing the human origin and evolution. Yet, experts say that the studies of these fossils and artefacts are far from being adequate and perfect in China because they have been plagued by many weak points.