Over time the descendants of the psychotic cannibals evolved into the subhumans on board, which was due to an enzyme given to the members during hyper-sleep that was supposed to both help their bodies adjust to the conditions on Tanis and speed up evolutionary natural selection.
Over time the descendants of the psychotic cannibals evolved into the subhumans on board who continue that culture. This was due to an enzyme given to the members during hyper-sleep that was supposed to both help their bodies adjust to the conditions on Tanis and speed up evolutionary natural selection.