BY EMILY COX AND HENRY RATHVON
ACROSS
1. What a serious birder maintains (2 wds)
5. Cut, as DNA with CRISPR
8. Author of A Natural History of the Senses
9. Founder of the Sierra Club
11. Pursuit involving drones
14. Happening by chance, like some mutations
15. Bone between knee and ankle
17. Cephalopod in 20,000 Leagues Under the Sea and Dr. No (2 wds)
20. Substance with a pH lower than 7
21. “Lucy” or “Ardi,” in anthropology
22. What digitigrades go on
23. Collective DNA of a population (2 wds)
DOWN 1. Photosynthesis factory 2. Like jackalopes or “Piltdown man” 3. Bass with a distinctive jaw 4. Apex predators of the sea 6. Source of a spiral in nature 7. Landlocked country with jaguars, tapirs, and harpy eagles ...