Bro Roberts considered the flood to be local (but to have killed all humans bar Noah and family). His comments are reproduced below:
“Considering the comparatively limited extent of the human family at the time, and that it was confined to one small district of the globe, it would seem reasonable to conclude from the principle already looked at-the divine sparingness of means-that the flood was co-extensive only with the Adamically-inhabited portion of the globe.
There are …facts that compel such a conclusion: and as all facts are of God, they must be in agreement. The animals of New Zealand are different from those of Australia. The animals of Australia, again, are different from those of Asia and Europe. These again differ entirely from those of the American continent: All differ from one another: and the fossil remains on all the continents show that this difference has always prevailed. Now if the flood were universal in the absolute sense, it is manifest that these facts could not be explained, for if the animals all over the earth were drowned, and the devastated countries were after-wards replenished from a Noachic centre, the animals of all countries would now show some similarity, instead of consisting of totally different species. The animals taken into the ark in that case would be the animals of the humanly populated district. Only a comparatively small district in relation to the face of the world at large.”
Roberts, R. “The Visible Hand of God”, The Christadelphian (18.205.308), 1881
Roberts thought therefore the flood was local, although he believed all humans were wiped out by the flood barring Noah’s family. Why did he come to this conclusion? Because of the natural evidence – the geographic distribution of species.
Consider also how did species make their way back to their respective homelands? Imagine the polar bears walking to the ice caps. They don’t cope well with 25 degrees, let
alone the middle eastern climes!
But worse – they couldn’t eat one of the two seals as this would cause extinction – so the bears would have to wait for their food source to breed a few spares. The dingos, travelling back to Australia in company with their various prey species would have to exercise similarly unnatural restraint. The weight of required miracles just increases exponentially to make this all work.
Whilst watching the dingos suffer, the koalas would have their own problem – they have a specialised diet of gum leaves, no food for them until they got home!