A few weeks ago, I was watching an episode of the Big Bang Theory, and Leanord purchases a prop from the H.G. Wells film, the Time Machine. In one scene [in the show] Leanord voices that he wishes he could go back in time and stop himself from buying the machine. To which Sheldon tells him that, should he do so--and assuming that he could-- then he would create a paradox; preventing him from purchasing the time machine would prevent him from going back in time, and thus eliminates his purpose for time traveling. And this has always confused me about time traveling. I mean, if you go back into the past to stop a certain occurance--like buying a time machine-- then your preventing the future action of travelling through time in the first place. It's confusing...I'm not even sure what I just wrote made any sort of sense...But it made me think about the Animorphs, and time travel paradoxes. In megamorphs three, they prevented John Berryman from being born, which seemingly prevents Visser Four from ever acquiring the time matrix, which--since the Animorphs had to use the time matrix, at least to some extent--means that the Animorphs never went back and time and THUS never prevented John Berryman from being born...
So really, the universe--the Animorph's Universe-- should have gone BOOM! from paradox.