Cacti are famous for their spine-shaped leaves, their water-retaining tissues, their green stems, and especially for being among the most well-adapted organisms on Earth for dry environments. This episode, we’re joined by Dr. Aly Baumgartner to discuss the diversity of cacti, their unique adaptations for an unusual lifestyle, and their mysterious evolutionary past.

In the news: Stone Age jewelry, kelp fossils, long-jawed fish, and early trees.

Time markers:Intro & Announcements: 00:00:00News: 00:06:00Main discussion, Part 1: 00:38:25Main discussion, Part 2: 01:25:00Patron question: 02:04:00

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The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org.

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/