How did animal get to isolated places after the flood?

I believe we can all agree that plants are much less mobile than animals are. So how did they migrate from eastern Turkey to their present localities, such that so many species are native to those localities and are not native to any other locality? Even though they can flourish in so many of those other localities, as evidenced by their success when transplanted (eg, palm trees in So Calif., Russian weed (AKA "tumble weed") in the western US).Furthermore, what about the animals who depend on specific plants, like koalas feeding on eucalyptus leaves. For that matter, considering how long it takes a eucalyptus seed to become a tree that koalas could feed on, how did adult trees get to Australia in time for the koalas to have something to eat? And how did those koalas find anything to eat in the meantime? Now apply that to all the other animal/plant relationships, including plants that need certain animals in order to survive or to propagate.slightly off-topic:
A similar plant-mobility question is raised by the mobility apologetic for explaining why explaining the order in which we find fossils, why "more advanced" fossils are found higher in the "flood deposits". The apologetic is that the more advanced animals could better see the Flood coming and high-tailed it to the high ground, leaving their "more primitive" brethern behind in the low lands to be buried in the lower layers.So what about the fossil distribution of plants? Were the "more advanced" plants able to also uproot themselves and flee to the high ground?