Lovers say they can’t live without each other, but in the case of the yucca moth and the Joshua tree, that might actually be true.

In a rare case of co-evolution, they need each other to survive: the Joshua tree can only be pollinated by the yucca moth, and the yucca moth can only survive eating the tree's seeds.

Biologist Chris Smith studied their relationship for 34 days in the desert. He worked with 1000 moths and a swath of trees. What did he find? And what makes our backyard so unique for this pair? Listen for the evolutionary love story of a moth and a tree.

GUESTS:

Chris Smith, assistant biology professor, Willamette University

• Joshua tree, yucca moth co-evolution fascinates researchers - LVRJ