If you don’t like your body, how would you like to regenerate a new one? It can be done, at least in slugs. Researchers have discovered two species of Japanese sea slugs that can shed their bodies and regrow new ones within three weeks.
I can understand why some humans would want to regrow their bodies, but why would a sea slug? That’s the part we haven’t figured out yet. We also don’t know what triggers what would normally be an act of self-destruction. One theory is this removes internal parasites that interfere with reproduction, or some other critical function.
And we certainly don’t understand the mechanisms involved. Perhaps a group of stem-like cells at the cut end of the neck are the regeneration drivers? If so, they’re pretty remarkable, since they have to replicate all the critical organs.
And how can a head survive that long without a body? One clue is the heads of relatively young slugs started to feed on algae within hours. Unfortunately, the castoff bodies apparently don’t regenerate heads; that would really be unbelievable.
This finding cries out for more research. Hopefully, someday these sea slugs will show us a way to regenerate our own tissues. Then someone saying “You act like a slug” will be a compliment.
For more details, including a video of the head and body of a sea slug moving spontaneously three days after separation, see “‘Wonder of Nature’: Self-decapitating sea slugs regenerate brand-new bodies” by Doyle Rice at https://www.usatoday.com/story/news/nation/2021/03/09/sea-slugs-decapitate-their-own-heads-then-regenerate-new-bodies/4643809001/.