TCRUD Discovery Speculation: So it seems Shifters regenerate much slower in their human form (like Eren in the forest with Reiner Bertholdt and Ymir). Hange mentions that the Titan head she kicked was wayyy lighter than it should have been. We've seen Eren regenerate a Titan hand in probably below 20 seconds in the anime, while his human arms took a few hours. Do you think Titans are much less dense in their physiology and their strength comes from their sheer size and regenerative ability? :D
This may be a factor, anon. Thank you for bringing it up.Â
Titan are the largest of the multi-cellular organisms to repair and maintain the integrity of their physiological and morphological states. As you mention, there are many aspects of titan regeneration to investigate, from the speed of titan regeneration to the exact signals that turn on regenerative processes. It would be helpful to discover why humanized shifters don’t regenerate at the rate titans do.Â
It’s important to note that all humans, not just shifters, can regenerate some organs, such as the liver. If part of the liver is lost by disease or injury it can rebuild. Of course Titans don’t have livers so there is no way we can do a comparison test of Titan vs Human liver regeneration to determine the speed and nature  of the process. It is hoped that the walled world will someday be able to isolate the specific cellular activity that causes the blastoma of cells surrounding a titan regeneration. It would be useful human medical purposes as well.
Thanks for the ask anon. I hope you will help me co-author and edit my future upcoming book that is never going to happen about Titan Physiology.
