But they would be wrong. Fossil evidence is only one of several separate lines of inquiry that contributes to the validity of the theory. If it was the only one, evolutionary theory would be somewhat of a (possibly unwarranted, though still convincing) extrapolation. However, morphological homology, biogeography, observed modification/speciation, and genetic sequencing also contribute to the pool of evidence (especially the last of these). Evolution is the simplest and only testable, unfalsified explanation that consistently unifies what we observe in all five of these data realms.
Are there any specific, testable physical predictions (or retrodictions, as you please) that intelligent design theory makes? Is there any test (other than our own credulity) that can differentiate between a mechanism that is intelligently designed versus one that evolved naturally (though we just don't know how yet)? If not, isn't it better to relegate such phenomena to the area of 'things we just don't know yet', and (out of honest necessity, at least at the present day) leave the existence of the 'Designer' to our personal faith?
You got somthin' against geology, astronomy (age of the earth & sun), physics (radiometric dating), and continental drift?