人類最古老祖先判明:五億年前的皮卡蟲大綱
A two-inch-long, worm-like sea creature is the earliest-known animal to have the beginnings of a backbone.
發現人類親緣最古老的祖先——一種2英寸長類似蠕蟲，聚集在海牀上的生物。劍橋大學的科學家證實，一種2英長類似蠕蟲的海洋生物是目前已知的最早的脊椎動物。
Cambridge University scientists have confirmed. This makes Pikaiagracilens, which evolved more than 500 million years ago, a precursor of modern vertebrates, including humans. The latest study resolves a debate about whether it is the first member of the chordate family. Humanbeings, as well as fish, amphibians, birds, reptiles and mammals are all descended from this two-inch creature —Pikaiagracilens which lived in the sea 505 million years ago.
這使得5億多年前就進化完成的一種生物——Pikaiagracilens(皮卡蟲)，成爲了現代脊椎動物的祖先，甚至還包括人類。這項最新的研究終結了一場關於它是否是脊椎動物家族中第一個成員的爭論。人類，還有魚、兩棲動物、鳥、爬行動物和哺乳動物等等，都起源於這種2英寸的生物——Pikaiagracilens，一種5.05億年前生活在海洋的生物。
