common ancestor

例句：

1. 1. The common ancestor of all humans is believed to be the Neanderthal.
   所有人类的共同祖先被认为是尼安德特人。
2. 2.The discovery of a common ancestor for all humans has been hailed as a scientific breakthrough.
   发现所有人类共有的祖先被视为科学上的突破。
3. 3.The study of genetics has led to the identification of common ancestors in various human populations.
   遗传学的研究已经识别出了不同人类群体的共同祖先。