中新网西安9月29日电 (记者 阿琳娜)从蜗牛的壳、螃蟹的甲，到人类的骨头——动物的"硬骨架"是怎么 来的？地球上的动物骨骼是如何长出来的？ 西北大学29日对外公布，该校张志飞教授指导博士研究生胡亚洲及团队成员，联合课题组外专Timothy Topper和Luke Strotz教授及中国科学院南京地质古生物研究所李国祥研究员与潘兵博士，对产自中国华 北板块寒武纪早期猴家山组的开腔骨骨片开展了系统研究，成果以亮点封面论文发表在美国地质学会著 名期刊——GEOLOGY。团队发现，5亿年前的化石里藏着动物最早由上皮组织控制骨骼生长的证据， 刷新了人类对早期动物的认知。 开腔骨骨片上多边形有机质框架结构包覆在磷酸盐化内核上，同时被磷灰石质外模包围，透射电镜能谱 分析揭示多边形结构以黏土矿物保存。西北大学供图 据介绍，动物是显生宙地球上的创新主角。珊瑚、腕足动物、软体动物和管栖环节动物(原口动物)等往 往具有防御用外骨骼，棘皮动物和各种脊椎动物等(后口动物)往往具有支撑身体的内骨骼。现代生物学 的研究认为原口动物和后口动物骨骼的矿化机制和生理过程可能不同，但均是在上皮组织或者结缔组织 控制下形成的矿化结构。那么，现如今 ...

Core Viewpoint - The research highlights the mitochondrial origins of sleep pressure, suggesting that sleep is not merely a resting state for the brain but a crucial maintenance process for the body's energy supply system [4][11]. Group 1: Research Findings - A study published in Nature reveals that sleep pressure arises from ATP surplus in specific brain cells, indicating a physical basis for sleep drive [4]. - The research team conducted a comparative analysis of the single-cell transcriptome characteristics of fruit flies under sufficient sleep and sleep deprivation, finding significant gene expression changes related to mitochondrial respiration and ATP synthesis in sleep-deprived flies [6][11]. - Mitochondrial fragmentation and increased mitochondrial-autophagy were observed in affected neurons, which could be reversed by restoring sleep [6][9]. Group 2: Mechanisms of Sleep Regulation - The study found that mitochondrial dynamics (fusion and fission) significantly influence the excitability of sleep-regulating neurons, thereby affecting sleep demand [9][11]. - During wakefulness, especially under sleep deprivation, the activity of these neurons is suppressed, leading to increased ATP concentration due to reduced consumption [9]. - Manipulating mitochondrial dynamics can either enhance or reduce sleep duration, indicating a direct link between mitochondrial function and sleep regulation [9][11]. Group 3: Implications and Future Directions - The findings provide insights into the relationship between metabolism, sleep, and lifespan, suggesting that sleep may be an unavoidable byproduct of aerobic metabolism, similar to aging [10][11]. - The research opens new avenues for understanding sleep disorders and their potential interventions by targeting mitochondrial function in specific neurons [11].

Core Viewpoint - The establishment of the "golden nail" in Guizhou, China, represents a significant advancement in global geological standards, providing a precise reference point for defining geological time scales and enhancing China's influence in earth sciences [3][4][12]. Group 1: Definition and Importance of "Golden Nails" - "Golden nails" are not literal nails but refer to globally recognized geological markers that define the boundaries of geological time units, serving as a standard for stratigraphic classification [4]. - The concept of "golden nails" addresses the historical lack of a unified standard for geological time scales, which has led to significant discrepancies in stratigraphic classification across different countries [4][6]. Group 2: The Significance of the Guizhou "Golden Nail" - The "golden nail" in Guizhou, set to be established in June 2025, is the 69th globally and the 11th in China, recognized for its exceptional geological and paleontological conditions [6][9]. - The site in Guizhou was selected due to its rich fossil record, accessibility, and long-term research conducted by local experts, meeting the stringent criteria set by the International Stratigraphic Commission [6][7]. Group 3: Geological Insights from the "Golden Nail" - The Guizhou "golden nail" will help define the Cambrian period's third system and fifth stage by identifying the first appearance of specific trilobite fossils, which are crucial for understanding geological events from 506 million years ago [9][10]. - The site provides vital evidence for the Cambrian explosion, a significant evolutionary event characterized by a rapid increase in biodiversity [10]. Group 4: Implications for China's Geological Research - The establishment of 11 "golden nails" in China underscores the country's growing capabilities in geological research and its enhanced standing in the global scientific community [12]. - Protecting these geological sites is essential, as they face threats from natural erosion, geological hazards, and human activities, necessitating a collaborative effort for their preservation [12].

Core Insights - The research team led by Professor Zhang Zhifei from Northwest University has successfully uncovered the mystery of Cambrian small shell fossil preservation after seven years of effort [1][2] - The study reveals that small shell fossils can be preserved through various methods, including phosphatization, dolomitization, and glauconitization, with phosphatization not being the dominant preservation method in the late Cambrian [1][2] Research Findings - The research involved the acid treatment of nearly 8 tons of Cambrian carbonate rock samples, resulting in the successful extraction of over 35,000 small shell fossils [2] - Advanced analytical techniques such as micro-X-ray fluorescence spectroscopy and scanning electron microscopy were employed to discover the diverse preservation methods of small shell fossils [2] - The study confirms that phosphatic deposition is not the primary factor controlling the production of high-quality small shell fossils, suggesting alternative preservation mechanisms [2] Implications - This research provides a new perspective for the search and interpretation of early life fossils, demonstrating that life evolution evidence can be preserved even under unfavorable conditions lacking phosphates [2] - The findings are expected to significantly advance the understanding of the mineralization mechanisms of animal skeletons and the early evolutionary processes [2]

今天，我们再一次迎来国际生物多样性日。今年的主题是 "万物共生 和美永续" ，呼吁以人与自然和谐共生之 道，创和美永续之路，进而推进全球生物多样性保护治理新进程。 最早拥有三色视觉的动物是一类 非脊椎动物——节肢动物 （如昆虫、蜘蛛和甲壳类动物） 。而在4.2亿至5亿 年前， 脊椎动物 也开始具备三色视觉，使它们能够比单色视觉的生物更精准地识别猎物和捕食者，提高在 环境中的导航能力。 化石证据提供了进一步的线索。例如， 三叶虫 ——一类生活在5亿多年前的已灭绝的海洋节肢动物，就拥 有 复眼 。这一视觉结构能够探测多种光波长，使三叶虫在昏暗的海洋环境中获得进化优势，提高运动感知 能力和生存竞争力。 这些证据表明，生物在自身变得五彩斑斓之前，便已具备感知色彩的能力。 地球生命共同体的每一次脉动，都与人类命运息息相关。从灰棕、柔和的主体色彩到今日的五彩斑斓，从雄孔 雀炫目的羽毛到绚烂多姿的花朵，地球历经了一系列的进化——生命的色彩是基因密码的具象表达，是物种生 存的底层逻辑的体现。在这个过程中，生物多样性构筑了人类生存的根基。 但一个不可否认的事实是：全球众多物种的遗传多样性正在加速丧失，那些承载着适应潜能的基因宝 ...