Every great thing must eventually come to an end.
- The crummy state of affairs back on Earth, with pollution, overpopulation and environmental degradation having ruined the ecosystem and turned the planet into a Crapsack World. The Yma are helping humanity fix the planet...but it was too late to save its wildlife, as most of its large animals are now extinct, and the last few remaining in shoddy, run-down zoos, and afflicted with horrible disfigurements.
- The death of the elderly Groveback as described in the book, with it "taking a long time to settle into what would be its final resting place, until all was still".
- The animals' death in the documentary may be worse. Considering the poor thing was slowly poisoned to death.
- Two of the Yma scientists perish in an accident on Darwin IV, and as a final tribute to them all traces of their presence on the planet were quickly disposed of, an act that Barlowe muses "would be something they would have appreciated".
- The book describes the Author Avatar as greatly missing his family back on earth, and how seeing the Unths tending their young or the Sac-Bac visiting its buried mate fills him with a longing for them.
- The author in the book accidentally injures a Finned Snapper with his vehicle which later perishes from its wounds, an incident that affects him greatly.
- In the documentary adaptation Alien Planet, the fates of Ike and Leo may count. After all the adventures we traveled with these probes, they're just violently beaten to 'death' by a bunch of Eosapiens who misundertood their gestures, a tragic end for the surprisingly adorable probes.
