We revisit our conversations with authors of some of the year’s most fascinating science books in our annual holiday book show. Featuring:

• Questioning the purpose of whale song — for love or echolocation?
• Journeying through deep geological time to better tackle problems of the future
• Biological sex is complicated, but that's what helps animals like humans thrive

Plus, science journalist and BookLab podcast co-host Dan Falk reviews The Martians by David Baron, Dinner With King Tut by Sam Kean and The Mind Electric by Pria Anand.