5 ms·

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell woul

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

cmdrfred 10y ago
This has to be a solved problem unless the womb offers some sort of telemetry.
- deleted 10y ago
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- MichaelBurge 10y ago
  In that case, the entire organism is forming. It can use techniques like forming the general structure before filling in the details. It could be that forming the general structure is carefully scripted by chemistry, while the details are mostly position-independent. Bones can have their lengths determined by biological clocks that operate over years. Examples of clocks are hormone release cycles, which the rest of the body uses for signaling. But, a new leg wouldn't have access to the global clock, since it would've shut off if the affected parts are fully-developed. Bones and muscles might have their final shapes partially determined by outside forces. The biggest one is gravity. It may be that people develop longer legs in space, or their spines don't develop correctly. A leg intended to be regrown on an adult might not have time to be shaped in this manner.
jonknee 10y ago
It's more than just worms that regenerate body parts. Some salamanders can regenerate whole limbs. https://www.youtube.com/watch?v=EsCSwVx3GvA https://www.youtube.com/watch?v=EsCSwVx3GvA
shripadk 10y ago
I remember seeing a story on BBC a while ago about how one guy, who lost the top portion of his finger while operating a toy in his hobby shop, was able to regrow it completely. It only took 4 weeks to regrow, including the nails, fingerprints et al., exactly as it was before using extracellular protein from pig bladder. Here is a link to the story: https://www.youtube.com/watch?v=NEnLK0oJCa8 https://www.youtube.com/watch?v=NEnLK0oJCa8

cmdrfred 10y ago

This has to be a solved problem unless the womb offers some sort of telemetry.

deleted 10y ago
[deleted]
MichaelBurge 10y ago
In that case, the entire organism is forming. It can use techniques like forming the general structure before filling in the details. It could be that forming the general structure is carefully scripted by chemistry, while the details are mostly position-independent. Bones can have their lengths determined by biological clocks that operate over years. Examples of clocks are hormone release cycles, which the rest of the body uses for signaling. But, a new leg wouldn't have access to the global clock, since it would've shut off if the affected parts are fully-developed. Bones and muscles might have their final shapes partially determined by outside forces. The biggest one is gravity. It may be that people develop longer legs in space, or their spines don't develop correctly. A leg intended to be regrown on an adult might not have time to be shaped in this manner.

jonknee 10y ago

It's more than just worms that regenerate body parts. Some salamanders can regenerate whole limbs. https://www.youtube.com/watch?v=EsCSwVx3GvA https://www.youtube.com/watch?v=EsCSwVx3GvA

shripadk 10y ago

I remember seeing a story on BBC a while ago about how one guy, who lost the top portion of his finger while operating a toy in his hobby shop, was able to regrow it completely. It only took 4 weeks to regrow, including the nails, fingerprints et al., exactly as it was before using extracellular protein from pig bladder. Here is a link to the story: https://www.youtube.com/watch?v=NEnLK0oJCa8 https://www.youtube.com/watch?v=NEnLK0oJCa8