1. Early embryos of many species develop ancestral features. 许多物种的早期胚胎具有其祖先的特性。
2. This ancestral species might have evolved at a time when the islands were connected. 这种祖先物种可能是在岛屿相连的时候进化而来的。
3. Of today's different groups of algae, green algae are probably the most similar to ancestral plants. 在今天的众多藻类中，绿藻可能与植物的祖先最为相似。
4. If for any reason this does not happen, the ancestral feature may not disappear, leading to an atavism. 如果因为任何原因，这些事情没有发生，祖先的种种特性也许就不会消失，从而导致返祖现象。
5. The first, Paleo-Indian, wave more than 15,000 years ago was ancestral to all Central and South American Indians. 在一万五千多年前进行第一次迁移的是古印度人，他们是美洲中部和南部的印第安人的祖先。
