So imagine their surprise when they discovered they were in fact biological brothers.

所以，你可以想象，他们发现彼此是有血缘关系的兄弟时有多惊讶。

The ancient and recurrent history of humans recognizing bears as either spiritual or biological brethren sets the tone for the book, which provides rich lessons for understanding our ursine neighbors and how their lives have intertwined with our own.

人类将熊视为精神或生物兄弟的古老而反复出现的历史为这本书奠定了基调，这为了解我们的熊邻居以及它们的生活如何与我们的生活交织在一起提供了丰富的经验教训。