Regeneration
I've been doing a bunch of research so I can develop Surzi, the functionally immortal maneater featured in Petrichor and Shattered. I've been building out the lore behind Surzi's species and along the way I've learned a lot of interesting stuff about real-world animals.
Quick Facts
The earliest known observations of liver regeneration occurred in the 1880s. The phenomenon was confirmed (in rats) in the 1930s.
The forest on the floodplain of Kenya's Tana River appears to be slowly dying. It can't regenerate because the upstream dams have stopped the floods the region relies on.
It takes female golden orb spiders about a week to regenerate their silk after it's been harvested.
Scientists have invented a "self-assembling gel" that triggers nerve regeneration in mice and can help cure paralysis.
Three-banded panther worms are about the size of a Tic Tac and can regrow any part of its body if you cut it off.
Endless Arms
Some scholars think that octopuses (octopodes? octopi?) are the source of hydra myths. Imagine an octopus or a squid, then flip it on its side. Now imagine the big bulbous head is actually its body. Now imagine its arms — which can regenerate — are actually long necks. Compare that mental image to this visual. Pretty wild, huh?
Complex Cells
Though salamanders are significantly larger and more complex than worms, they can also regenerate almost anything — including their spinal cords and eyes. The axolotl has the largest genome ever fully sequenced, and has about ten times the base pairs of human DNA. Scientists are still trying to figure out how they make the cells near the site of an injury revert to stem cells and help us live forever.
Eating Liver
The Prometheus myth, in which a god is has his liver eaten every day as punishment for giving the gift of fire to humans, is a popular myth involving regeneration. It's probably just a coincidence, though: the ancient Greeks who told stories about Prometheus almost certainly didn't know about the liver's regenerative powers. Here's a really detailed explanation of how we know that.
Hollow Tails
When certain species of lizard are threatened, they can drop their tails to evade predators, then grow a new one over a few weeks or months. In most cases, the new tail is supported by cartilage, instead of bones and nerves. Scientists figured out how to implant gene-edited neural stem cells into adult lizards to get them to regrow "perfect" new tails.
📗 ICYMI: If you found this interesting, you may also enjoy my investigation into whether it would work for a fantasy culture to herd giant vegetarian spiders for their silk.
💚 If you learned something from this overview, consider forwarding it to a friend and encouraging them to sign up for more research deep dives into obscure history and science.
🧳 I'm headed to The 79th World Science Fiction Convention in Washington D.C. this week, so if you're planning to be there (or happen to live near Dupont Circle), let me know if you want to say hi in person!