The spreading of a change outward through what is connected. Propagation is why one edit can reach everything.
Latin propagare (to set forward, to breed, to extend), from pro- (forward) + pangere (to fasten, to fix); propagation was first about extending a plant by layering its shoots, and the sense of spreading outward through connection follows directly.
The spreading of a change outward through everything connected to it. The root's own image — a shoot fastened into new ground so it takes root there too — is exactly why one edit can reach everywhere at once.