In H.G. Wells' book "The Island of Doctor Moreau," a profound statement is made about the relationship between evolution and the existence of seemingly useless traits or entities. The quote suggests that everything that lacks purpose is eventually eliminated through the process of evolution. This highlights the idea that nature is selective, prioritizing survival and usefulness over time.

Additionally, the mention of pain as something that can become unnecessary emphasizes the complexities of existence and suffering. It invites readers to reflect on the nature of pain in both life and evolution, suggesting that just as useless traits are removed, perhaps unnecessary suffering could also be mitigated through understanding and adaptation. The exploration of these themes connects deeply with the broader narrative of the novel and raises important philosophical questions about purpose and the human experience.