寒武纪爆发是指大多数现代动物群体进化的时期，在570到5.3亿年前。寒武纪爆炸是指我们星球历史上前所未有的无与伦比的进化创新时期。在寒武纪爆发期间，早期生物进化成许多不同的，更复杂的形式。在此期间，几乎所有持续存在的基本动物身体计划都应运而生。第一批背脊动物，也被称为脊椎动物，在寒武纪时期发展到大约5.25亿年前。最早的已知脊椎动物被认为是Myllokunmingia，一种被认为具有头骨和由软骨制成的骨骼的动物。今天，大约有57,000种脊椎动物，占我们星球上所有已知物种的约3％。今天活着的另外97％的物种是无脊椎动物，属于动物群体，如海绵，刺胞动物，扁虫，软体动物，节肢动物，昆虫，分段蠕虫和棘皮动物以及许多其他鲜为人知的动物群。第一批陆地脊椎动物在大约3.6亿年前进化。在大约3.6亿年前，居住在陆地栖息地的唯一生物是植物和无脊椎动物。然后，一群鱼知道叶鳍鱼类进化了必要的适应性，以实现从水到陆地的过渡。在3亿至1亿5千万年前，第一批陆地脊椎动物产生了爬行动物，而这些爬行动物又产生了鸟类和哺乳动物。第一批陆生脊椎动物是两栖四足动物，有一段时间与它们出现的水生栖息地保持密切联系。在它们进化的过程中，早期陆地脊椎动物进化出适应性，使它们能够更自由地生活在陆地上。一种这样的适应是羊膜蛋。今天，包括爬行动物，鸟类和哺乳动物在内的动物群体代表了那些早期羊膜动物的后代。
英国华威大学生物论文代写：早期生物进化
The Cambrian explosion refers to the period of evolution of most modern animal groups, between 570 and 530 million years ago. The Cambrian explosion is an unparalleled period of evolutionary innovation in the history of our planet. During the Cambrian explosion, early organisms evolved into many different, more complex forms. During this period, almost all of the persistent basic animal body plans came into being. The first batch of back-to-back animals, also known as vertebrates, developed to about 525 million years ago during the Cambrian period. The earliest known vertebrate is considered to be Myllokunmingia, an animal believed to have a skull and bones made of cartilage. Today, there are approximately 57,000 vertebrates, accounting for about 3% of all known species on our planet. The other 97% of the species that are alive today are invertebrates, belonging to animal groups such as sponges, cnidaria, flatworms, mollusks, arthropods, insects, segmented worms and echinoderms, and many other lesser known fauna. . The first terrestrial vertebrates evolved about 360 million years ago. About 360 million years ago, the only organisms that inhabited terrestrial habitats were plants and invertebrates. Then, a group of fish knew that the finfish evolved the necessary adaptability to achieve a transition from water to land. Between 300 million and 150 million years ago, the first terrestrial vertebrates produced reptiles, which in turn produced birds and mammals. The first terrestrial vertebrates were amphibious tetrapods that had been in close contact with their aquatic habitat for some time. In the course of their evolution, early terrestrial vertebrates evolved adaptability, allowing them to live more freely on land. One such adaptation is amnion eggs. Today, animal populations including reptiles, birds and mammals represent the offspring of early amniotic animals.