I have often been amused by our vulgar tendency to take complex issues, with solutions at neither extreme of a continuum of possibilities, and break … - Stephen Jay Gould

South America had been an island continent, far bigger and far more diverse than Australia, for tens of millions of years before the Isthmus of Panama rose just a couple of million years ago. The resulting flood of North American mammals across the new land bridge corresponds in time with the decimation of the native South American fauna. In fact, most large mammals generally considered distinctly South American... are all recent migrants from North America.

Homo sapiens [are] a tiny twig on an improbable branch of a contingent limb on a fortunate tree.

Creative thought in science is exactly this - not a mechanical collection on of facts and intuition, bias, and insight from other fields. Science, at its best, interposes human judgement and ingenuity upon all proceedings. It is, after all (although we sometimes forget it), practiced by humans.