脊椎动物的起源与演化研究进展

脊椎动物的起源与演化历来是进化生命科学的核心命题。近年脊椎动物的起源与演化有重大突破。云南澄江寒武纪化石群中的后口类“皇冠西大动物” ,半索动物“云南虫”和“海口虫” ,尾索动物“始祖长江海鞘” ,头索动物“海口华夏鱼”和“中间型中新鱼” ,脊椎动物“凤姣昆明鱼”和“海口鱼” ,论证了普通无脊椎动物向脊椎动物演化过渡的各种中间类型 ,勾勒出一幅较为完整的早期生命演化谱系。西北大学早期生命研究所舒德干教授基于对靠近脊椎动物“源头”时段软躯体后口动物化石系列的研究以及新的发现提出脊椎动物起源分“五步走”的新假说 ,即在脊椎动物的起源的“四步走”前还有更为原始的“一步” :云南澄江出土的古虫动物门化石很可能代表了原口动物和后口动物间的过渡类型。本文即综述了普通无脊椎动物向脊椎动物演化的研究进展。

Advances in Vertebrate Origin and Evolvement

The vertebrate origin and evolvement has always played core role of evolution and life science. Recently,there have been vital Advances in vertebrate origin and evolvement. A pipiscid-like metazoan fossil:Xidazoon stephanus,hemichordate fossil:Yunnanozoon and Haikouella,unrochordate fossil:Cheungkongella ancestralis,craniate-like/cephalochordate chordate fossil:Cathaymyrus haikouensis and zhongxiniscus intermedius and vertebrate fossil:Myllokunmingia fengfiaoa and Haikouichthys ercaicunensis had been found in Yunnan Chengjiang Cambrian fauna and have been being investigated by many scholars. This demonstrates that these fossil are intermedial transitional types that evolved from invertebrate to vertebrate.Therefore,a comparatively integrated evolutivc tree was described. D-G Shu in early life institute of Northwest University proposed the hypothesis that there were five steps in vertebrate origin based upon series of investigations concerning metazoan soft-body fossils closed vertebrate headstream. Namely,there was keystone original step before the four steps in vertebrate origin.That is to say,those vetulicolia fossils unearthed in Yunnan Chengjiang Cambrian fauna are likely intermedial transitional types that evolved from protostomes to deuterostomes.This paper reviewed Advances in vertebrate evolved from invertebrate.