atavism

他蓝色的眼睛被认为是来自曾祖父的返祖特征。

His blue eyes were thought to be an ___atavism from his great-grandfather.

这个婴儿多出的手指被认为是来自远古祖先的返祖现象。

The baby's extra finger was thought to be an ___atavism from distant ancestors.

部落中重新出现的活人祭祀被视为一种令人不安的文化返祖现象。

The revival of human sacrifice in the tribe was seen as a disturbing cultural ___atavism.