And healthy equals young, for all practical purposes. It may turn out that growing new bodies for whole-body patients is even simpler than repairing them cell by cell. Look at what our bodies can do already. We can all grow skin over a cut. Our bodies can recover from the massive trauma of heart bypass surgery.
Young children can often regrow a fingertip severed in a car door.
The repairs possible in the future will be more extensive, because the field of medicine is putting a tremendous emphasis on accomplishing them. For instance, within 25 years, spinal injuries may not be paralyzing or fatal. Researchers are making steady progress in regrowing the connections in crushed or severed spinal cords. Our understanding of how cells operate and grow is expanding rapidly. Someday we will learn why the child can regrow that fingertip and use that knowledge to regrow entire missing limbs.