5亿年前,地球上最早的由无脊椎到脊椎的过渡——脊索动物在海洋里出现,这就是文昌鱼。经过了漫长的岁月。脊索动物演化为各种脊椎动物,其中包括类人猿,因此文昌鱼在物种起源方面具有世界意义。文昌鱼没有脊椎骨,不容易留下化石的遗迹,但神迹般没有灭绝,成为了历史见证者般的“活化石”。对此,达尔文曾说过一句话:“这是一个伟大的发现,它提供了揭示脊椎动物起源的钥匙。”因为 500 million years ago, the earliest invertebrate to spine transition on Earth - the chordate appears in the ocean, which is amphioxus. After a long time. Chordates evolve into a variety of vertebrates, including apes, so amphioxus has world significance in terms of the origin of the species. Amphioxus vertebra without vertebral bone, not easy to leave the remains of fossils, but miraculous as no extinction, has become the witness of history like “living fossils.” In response, Darwin once said: “This is a great discovery, it provides the key to reveal the origin of vertebrates.” Because