Creating the creators: if creation demands a visionary creator, then how does blind evolution manage to build such splendid new things as ourselves? - special issue: The Science of Creativity

Consider two crucial examples in the evolution of vertebrates: Since a fish's air bladder is the same organ as a mammals lung, many people assume that air bladders evolved into lungs (because mammals are supposedly "higher", than fishes). In fact, evolution took the opposite path: the lungs possessed by all early fishes became air bladders in most modem fishes but remained as lungs in the ancestors of terrestrial vertebrates. Since more than half of all vertebrate species are fishes with air bladders, this creative evolutionary transition represents a key event in the history of vertebrates f however demoted or ignored because we are so hung up on our own supposed superiority and don't like to credit fishes for altering a primitive organ like our lung to a different and highly successful function).

But how can a lung become an air bladder? How could such a transition occur without suffocation of the intermediary forms? A famous song tells us that fish gotta swim, but they also gotta breathe. The principle of redundancy resolves this riddle. Early fishes breathed with two organs@ gills and lungs (as do modem lungfishes, technically known as dipnoans - meaning "two breathing"). Thus, fish could continue to breathe with gills while lungs evolved to the novel function of air bladders.

The malleus and incus (hammer and anvil@ bones of the mammalian middle ear evolved from precursors that articulated the jaws of our reptilian ancestors. But how could such a creative transition occur? A vertebrate cannot survive with an unhinged jaw. Creationists have used this argument to claim that evolution is impossible and that mammals must have been specially created, not evolved from reptiles. But the principle of redundancy resolves this problem as well - not only by a clever theoretical argument but as a demonstrated fact, because the intermediate forms have been found as fossils. The intermediates evolved a double jaw joint - one between the old reptilian bones that would later enter the mammalian ear, and the other between the two bones that now form the jaw joint of mammals. Thus, one joint could disappear as evolution moved and transformed the bones for a different primary function of hearing - while the other joint continued to function in the necessary task of articulation.

At the genetic level, the principle of redundancy has an even more general expression in the phenomenon of gene duplication. If, as in many bacteria, each gene exists as a single copy and codes for an essential enzyme or protein, how could substantial change ever occur - for any major shift in function would annihilate an original use that remains essential for life?

The solution to this most general statement of a central paradox resides in a property of genetic material in eukaryotic organisms (nonbacterial creatures with complex cells, Including such unicellular forms as amoebas and paramecia, and all multicellular organisms). For a set of dimly understood and complex reasons, the genetic programs of eukaryotic organisms maintain a high level of redundancy, largely because many genes tend to duplicate themselves within the genetic program and therefore exist in multiple copies. As natural selection has no consciousness and cannot work for future benefits, this repeated DNA does not originate in order to provide the requisite flexibility that creative evolutionary change requires. Rather, such creative flexibility emerges as an evolutionary legacy, a fortuitous and unintended side consequence of DNA's tendency to produce multiple copies within the genetic programs of eukaryotic organisms. When multiple copies exist, the essential function can be maintained by some copies while others become available for evolutionary modification in substantially new and creative directions. If repeated DNA did not exist for its own immediate reasons, our world would probably be inhabited only by organisms of bacterial grade-a perfectly good alternative world to be sure, but one that could not include the writer and readers of this essay.