In a way, so had Bohlin. He never accepted the hypothesis central to his discipline, hardened in the crucible of 150 years of experimentation, validated by the advent of modern genetics. He could not believe that evolutionary mechanisms could account for the dizzying complexity he saw in the living world. It was easier for him to detect the work of some unseen force — a designer's hand guiding a spontaneous appearance of species — behind the rise of complex life. It's the sort of completely untestable idea that doesn't gain much traction among the editors and reviewers of scholarly journals.

And so, according to his own list of published work, Bohlin's name was never attached to another peer-reviewed scientific study after his paper on gophers in 1982. Faith in a theory for which there is no experiment turned out to be a dead end. Yet he may be the only creationist to have participated in naming a new species, which is exactly what makes him so valuable to a movement that has worked for decades to scrub Charles Darwin from Texas public schools.

On a recent morning in Plano, Bohlin stood beneath a chandelier made of antlers, roughly the size of a small truck, in theHope Center — some 185,000 square feet of hunting-lodge style, rough-hewn rock façade, rustic leather furniture and exposed wooden beams. It houses more than 40 separate Christian organizations in a complex on Plano Parkway, including Bohlin's own Probe Ministries. On the second floor, Probe fights for the everlasting souls of American youth from a warren of offices, balustered by rising stacks of science textbooks and Christian literature.

Bohlin looks like a college biology professor, pale, square-jawed, peering out through glasses beneath an Indiana Jones fedora emblazoned with the words "Grand Canyon." It's actually the subject of one of his trademark lectures. He takes his audience on a virtual tour of our national testament to unfathomable geologic time and offers explanations for how the biblical flood may have created it far later than mainstream science would have them believe.