Science does not yet possess a complete historical reconstruction of the origin of biological coding and translation.
Critics therefore argue that Intelligent Design simply places a designer into what science has not yet explained. If future research fills those gaps, would the design argument disappear?
This is an important challenge because ignorance of a natural explanation is not itself positive evidence for intelligent causation.
If the argument amounts only to "science cannot currently explain this, therefore God did it," then it would indeed depend upon a gap in present knowledge.
A sound Intelligent Design argument must do more than identify unsolved scientific problems.
Natural models involving chemistry, selection, coevolution, historical contingency, molecular recognition, and self-organization must be considered seriously. They should be allowed to explain whatever the evidence demonstrates that they can explain.
The positive design argument instead focuses upon characteristics actually observed in biological systems: sequence-specific functional information, coding relationships, molecular recognition, coordinated translation, error control, and integration among information-processing components.
The question then becomes comparative. Do known and proposed natural mechanisms provide an adequate account of the origin of these features, or does purposeful causation provide a reasonable explanation of them?
For the Christian, unanswered scientific questions are not the foundation for belief in a Creator. Scripture already presents creation as purposeful. Intelligent Design asks the narrower evidential question of whether characteristics observed in nature itself also reasonably point toward purpose.
Can proposed natural mechanisms be extended into experimentally credible pathways for the origin of coding and translation?
What positive characteristics would distinguish evidence for purposeful causation from a temporary absence of knowledge?
What future discoveries would weaken a design interpretation, and what discoveries would strengthen it?