测量出1个电子的电流

近年来，在人类起源问题上流行着一种说法，即认为早期的人类出现在非洲，然后逐渐扩散到欧亚大陆。为了寻找人类最初产生于非洲的证据，最近，人们把目光集中到了格鲁吉亚。     

国家自然科学奖一等奖——“澄江动物群和寒武纪大爆发”

2003年度国家自然科学奖揭晓：中国科学院南京地质古生物研究所陈均远教授，西北大学舒德干教授和云南大学侯先光教授共同完成的“澄江动物群和寒武纪大爆发”获得一等奖，由于三位获奖者从不同方面做出了各自的贡献，并列第一，这在我国自然科学奖评奖史上尚属首次。     

发现“许昌人”

现代人起源于非洲已成主流观点。但是,在河南省许昌市许昌县灵井旧石器时代遗址中,不久前出土的距今8万～10万年的“许昌人”头盖骨化石对中国现代人“非洲起源说”提出了挑战。作为发掘队的领队,本文作者饱含激情地讲述了这一重要发现的经过及其所蕴含的意义。     

辽西惊现四翼恐龙

辽西是个神奇的地方。那里出土了各种长羽毛的恐龙的化石．为解开鸟类起源之谜不断地增加着新线索。不久前，新的发现再次震惊了世界——长着四个翅膀的顾氏小盗龙“飞”上了《自然》杂志的封面，解开鸟类起源之谜似乎近在咫尺了。     

A rare lobopod with well-preserved eyes from Chengjiang Lagerstātte and its implications for origin of arthropods

The origin of arthropods has long been one ofthe most hotly-debated subjects. Arthropods used to bethought closely related with annelids, but the two groups arenow believed to be separated into two major realms withinProtostomia on the basis of new molecular data. Although itis generally held by paleontologists that arthropods should berooted in the early lobopods-.a kind of worm-like creaturewith non-segmented legs, no intermediate forms have beenfound to bridge them. Here we report an organism with amixture of characters, including features characteristic ofarthropods (e.g., primary cephalization with paired eyes,paired antennae, and preliminary tagmosis) and of lobopods(e.g., worm-like body design, the dorsal spines, andnon-segmented limbs or lobe-like legs). The discovery of therare transitional form may throw new light on the origin ofarthropods and suggests that the most primitive arthropodsbegan with paired uniramous legs and the biramous onesevolved later.     

几乎所有动物祖先站在同一起跑线上--5.3亿年前化石揭秘"寒武纪生命大爆发"

“寒武纪大爆发”是一个令达尔都感到困惑的问题，在人们普遍认同达尔进化论的今天，全面揭示并合理解释“寒武纪大爆发”的真实面貌、探索众多动物门类起源的难题仍然摆在人们面前。     

The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age

One of the most hotly debated and frontal issues in paleoanthropology focuses on the origins of modern humans. Recently, an incomplete hominin mandible with a distinctly weaker mental protuberance than modern human and a great variety of coexisting fossil mammals were unearthed from the Homo sapiens Cave of Mulan Mountain, Chongzuo, Guangxi. The mammalian fauna from the Homo sapiens Cave characterized by the combination of Elephas kiangnanensis, first occurring Elephas maixmus, and Megatapirus augustus, and strikingly different from the Early Pleistocene Gigantopithecus fauna and the Middle Pleistocene Ailuropoda-Stogodon fauna of South China could be regarded as an early representive of the typical Asian elephant fauna. Faunal analysis, biostratigraphic correlation, and, most importantly, U-series dating all consistently support an estimate of ca. 110 ka for the age of the fossil Homo sapiens and coexisting mammalian fauna, that is, the early Late Pleistocene. The fauna is mainly made up of tropical-subtropical elements, but grassland elements have a much greater variety than forest elements, which probably indicates a drier climate at that time. This discovery of early Homo sapiens at the Mulan Mountain will play a significant role in the study of the origin and its environmental background of modern humans.     

瓮安生物群胚胎化石揭示后生动物起源及早期演化历程

包括人类在内的复杂多细胞动物的始祖是什么时候开始出现在地球上的?这是科学界最引人入胜但知之甚少的重大科学问题之一,解决这一难题恐怕只能依靠化石的发现和研究.     

“许昌人”头盖骨：现代人类起源再诠释？——“许昌人”头盖骨对国际学术界的挑战

“许昌人”头盖骨的发现,印证了“多地区起源”及人类连续进化附带杂交模式学说的正确性,面对“许昌人”头盖骨,“非洲夏娃说”、“代替说”等不攻自破。“许昌人”不仅可能是北京猿人的后代,同时还应是现代中国人的祖先。同时“许昌人”头盖骨的发现在人类学研究领域对DNA的科学证明提出了严峻挑战。它以事实提醒我们,面对现代人类多源说的实证资料,在人类学、考古学和基因科学诸多学术研究领域里调整学术思路势在必然。     

哺乳动物毛发起源之谜

毛发是哺乳动物的一个决定性特征，所有哺乳动物身上都有毛发，即便是很多一眼看上去“无毛”的哺乳动物，包括大象、河马、犀牛、鲸鱼、海豚和其他鲸日动物也部分覆盖着很细的短毛发。毛发拥有许多功能，包括保温、第二性征、吸引配偶，保护皮肤、反射和吸收阳光等。     

Carbon and nitrogen stable isotope analyses of mammal bone fossils from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River,China

Based on AMS ¹⁴C dating data, carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer, cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River. These analyses were conducted to reconstruct palaeodiets of mammals, palaeoecology, palaeoenviroment and previous human activities in the study area. Results show that the collagen loss of bone did not change the in vivo isotopic composition of carbon and nitrogen stable isotopes, and most of the bone fossils were well preserved. The bone collagen of samples from deer had a mean δ¹³C of -23.1‰ and a mean δ¹⁵N of 4.7‰, suggesting that deer subsisted in a closed habitat and fed on branches and leaves. The bone collagen of cattle had a mean δ¹³C of –19.6‰ and a mean δ¹⁵N of 5.2‰, which indicates that cattle subsisted in an open habitat and fed on grasses and stems. The δ¹³C values show that both deer and cattle fed on C₃ plants and lived in the same ecosystem, but the t-test results show that deer δ¹³C and δ¹⁵N values were both more negative than those of cattle, indicating that they inhabited different niches. The δ¹³C and δ¹⁵N values of cattle partially overlapped those of deer, suggesting some competition in diets between them. The t-tests show that the δ¹³C and δ¹⁵N values of pigs were more positive than those of cattle and deer, which signifies that pigs occupied a higher trophic level compared to cattle and deer. The wide range of pig δ¹³C values demonstrates that pig trading had been taking place from early Neolithic Age to late Bronze Age. There were no significant differences in deer δ¹³C and δ¹⁵N values among different archaeological periods, making it clear that climatic, ecological and environmental conditions were kept relatively stable from 2200 to 4200 a BP. This stability may have been responsible for the extensive and complete cultural layers at the Zhongba site. The minimum number of samples required to estimate the mean δ¹³C values of deer, pigs and cattle are 8, 73 and 16, respectively, and for mean δ¹⁵N values of deer, pigs and cattle, the minimum numbers are 4, 5 and 6, respectively.     

行摄非洲草原动物大迁徙

正没有硝烟的"长枪短炮"每一个见证动物迁徙的游客都会渴望能将这一瞬间记录下来。在命,是非洲动物大迁徙永恒的主题。数百万计的角马和斑马浩浩荡荡,追随着雨水和嫩草长途迁徙至此,期间更是需要逃生于食肉动物的追随捕杀、马拉河汹涌河水以及潜伏四周的种种危险。滚滚而来的蹄声和漫天扬起的尘土,万"马"奔腾的壮观场景最好地诠释了它们对于生命的渴望。冷峻的眼神、满嘴的鲜血,食肉动物用自己的速度和力量演绎着大草原上每天的生死对决,享受着一年一度的丰盛大餐季节。狮子、猎豹、花豹、鬣狗、秃鹫、鳄鱼,这些食物链顶层的统治者们用赤裸裸的杀戮讲述着草原上弱肉强食、适者生存的不变真理。在众多位于东非的国家公园中,尤以肯尼亚境内的马赛马拉最为著名,这一片广袤的东非大草原上栖息着百万计的野生动物,是世界上大型哺乳动物密度最高的地方,我们所看过的《国家地理》、《动     

科技旅游系列报道之神奇动物游 动物世界也精彩

相信大家都对"动物是人类的朋友"这句话并不陌生,这可不是到了现代才出现的,早在几千年前,孔子就曾在《生灵之道》一文中,写下"万物生灵乃人类之益友"这样的句子。那么,您对我们的朋友到底了解多少呢?它们又经历了怎样的演化过程呢?本期"神奇动物游",我们将带您畅游中国古动物馆、北京富国海底