我们的祖先从水里来--硬骨鱼类起源与早期演化

From fish to human: Origin and early evolution of osteichthyans

硬骨鱼类(osteichthyans)是脊椎动物演化的主干,硬骨鱼下分的两大支系,即肉鳍鱼类(lobe-finned fishes)和辐鳍鱼类(ray-finned fishes)分别成为今日地球陆地和水域的征服者,前者最终演化出包括人类在内的四足动物。志留纪—泥盆纪是硬骨鱼类乃至整个有颌脊椎动物演化的关键阶段,硬骨鱼纲的起源、辐鳍鱼类与肉鳍鱼类的分异、肉鳍鱼类的早期演化和四足动物的起源等关键演化事件都出现在这一时期。直到20世纪末,化石资料的匮乏长期以来一直限制着学界对这些硬骨鱼类起源与早期演化关键事件的了解。近年来,来自中国的梦幻鬼鱼、初始全颌鱼、晨晓弥曼鱼、于氏箐门齿鱼和奇异东生鱼等一系列关键化石的发现与研究极大地改变了上述情况,将硬骨鱼类起源与早期演化推到早期脊椎动物研究的聚光灯下,为脊椎动物"从鱼到人"的演化历史补上了大量缺失的篇章。

Osteichthyans （bony fishes and tetrapods） form the trunk of vertebrate evolutionary tree. Two osteichthyan clades, namely sarcopterygians （lobe-finned fishes and tetrapods） and actinopterygians （ray-finned fishes）, conquer the lands and waters of modern earth respectively. The lobe-finned fishes gave rise to the tetrapods that include all the terrestrial vertebrates and human ourselves. Silurian to Devonian is an important period in osteichthyan, as well as jawed vertebrate evolution, during which time major events such as the origin of osteichthyans, the divergence of sarcopterygians and actinopterygians, the early evolutionary history of sarcopterygians and the rise of tetrapods occurred. As late as the end of last century, the lack of substantial fossil evidence severely hampered our understanding of these events. This situation is only improved when a series of transitional fossils from China, e.g. Guiyu oneiros, Entelognathus primordialis, Meemannia eos, Qingmenodus yui and Tungsenia paradoxa, have been discovered and studied in recent years. These new evidences help the origin and early evolution of osteichthyans to become one of the spotlight topics in vertebrate paleontology, recovering long lost chapters in the history of evolution from fish to human.