There are fundamental, unbridgeable chasms on either side, animal and machine. The capacity for creativity, for one thing, stands permanently outside the reach of algorithms.
A scientific theory that on principle refuses to see the obvious is an achievement of which only humans are capable.
Following Darwin, with an assist from Stephen Jay Gould and Richard Lewontin, Ken Miller proposes that human reason, consciousness, etc. are exaptations, or “spandrels.”