Only evolutionists could claim koalas are bears.
This is a particularly ignorant statement. No "evolutionist" claims that koalas are bears. In fact I just visited a koala exhibit at a zoo. The very first sign says, Koalas are not bears.
Riiight...and birds are dinosaurs...LOL.
Birds and dinosaurs share a common ancestor but there is still debate as to how far back that common ancestor was and whether or not some species of dinosaurs, especially the raptors may have actually been flightless birds.
Bird-from-dinosaur theory of evolution challenged: Was it the other way around?
Meanwhile it is quite clear that as the OP suggests, biogeography is totally inconsistent with the idea that all the animals on earth are descended from ancestors that came off a boat in the Middle East a few thousand years ago.
Below is quote from the OP of an old thread of mine on the subject
http://www.christianforums.com/t155813/
The Problem
According to the ark story marsupials and the other unique animals in Australia, New Zealand and New Guinea would have had to get there after coming off a boat, in pairs, in the Middle East into a flood devastated world along with representatives of all other land dwelling animals extinct and extant.
Overall there are 13 families and about 180 unique species of marsupials in the area including kangaroos and kolas and marsupial mole like animals (of the Order Notoryctemorphia) that only live in sand. The only monotremes (egg laying mammals) in world, the platypus and 2 species of echidna are found in the Australia and New Guinea and nowhere else on earth. The Kiwi, a flightless bird, lives in New Zealand which has no native mammals of any kind.
How is it that the marsupials and monotremes made it to Australia where they just happen to exist in fossil record while thousands of species of placental mammals that just happen not to exist in the Australian fossil record did not?
There is no evidence that modern marsupials or monotremes ever lived in Europe, Asia or Africa and the only marsupial fossils ever found on those continents are of very primitive marsupials. The only placental mammals either fossils or extant prior to the arrival of man found in Australia are bats, a couple species of rats and the teeth of a very primitive placental mammal.
How did marsupial mole like animals make it at all, let alone getting there ahead of all those placental mammals? These are animals that only live in sand. Of course this is far from being the only problem. The three-toed sloth can only drag itself slowly on the ground it cant walk. It can't tolerate low temperatures and moves only about 1 mile a month. How did they make it to the Americas, where sloths just happen to exist in the fossil record? Where they of a fast moving, migrating, cold tolerating kind a few thousand years ago? Does this really make any sense? If they could get around so well why did they only get the Americas where sloths happen to have a fossil record??
The giant spiny anteater (one of the echidna species) is also a slow moving clumsy animal but is supposed to have made it to New Guinea ahead of all nearly all the placental mammals.
The koala only lives in Eucalyptus trees and travels very little if at all. Yet they supposedly came off an ark in the middle east and somehow got to Australia.
The kiwi is a chubby little flightless bird that somehow made it to New Zealand where it had fossil relatives, with no mammals of any kind for company.
How is it that Gila monsters got to the American Southwest and why did they not go to the much more convenient deserts around the Middle East instead? Did these desert reptiles cross an ice age land bridge? How did armadillos make it to the Americas while wildebeest, zebras and giraffe did not?
The question is not only how these animals got where they were going but also why other animals equally well adapted for the destination and in many cases far more able and likely to travel did not.