In 2005, I wrote a profile of the geneticist Francis Collins that referred to him as an apostle of genetics. Then the director of the Human Genome Research Institute at the National Institutes of Health, Collins was, and is, an evangelical Christian who also believes strongly in evidence-based science and evolution--and in spreading the word about the power of genetics and molecular biology to radically reshape medicine and society.

Whether talking to members of Congress, high-powered scientific leaders from around the world, one of his patients, or students in his lab, Collins's zeal and ambition for pushing his vision of science is palpable and intense--and often delivered with a rural Virginia drawl that puts listeners at ease even as he aggressively pushes his agenda.

He acquired his aw-shucks demeanor--and penchant for wearing flannel shirts and corduroy pants--growing up in the Shenandoah River Valley in Virginia. His parents came from New York City but checked out of urban life to run a back-to-nature farm, and to produce a professional summer Shakespeare theatrical company. Folk singers often showed up when he was a boy, and Bob Dylan spent his 18th birthday in the Collins farmhouse.

A man who loves to speak and to play his guitar--he was recently shown with his ax dressed like Bon Jovi in a GQ spread called "Rock Stars of Science"--Collins learned to be skilled at performing and persuading, he told me, by playing roles in his parents' plays. At the age of seven, he wrote a children's play version of The Wizard of Oz and played a role uncharacteristic for this firebrand of science: the Cowardly Lion.

He first trained as a chemist, then became a physician, discovering God while trying to sort out the mysteries of life and death at age 27 during his residency at the University of North Carolina. He later landed at the University of Michigan, where he drew attention for codiscovering the gene mutations for cystic fibrosis in 1989. In 1993, he received an unexpected invitation from then director of the NIH, Bernadine Healy, to succeed James Watson as the head of the Human Genome Project--which Collins first declined, but later accepted.

Collins has a preference for big ideas, and has continued to organize large-scale projects to map and organize the genomes of humans and other organisms. Lately, he has been pushing a stronger linkage between environmental factors, such as chemical pollutants and stress, that interact with genes, calling for a $400 million increase in the Gene Environment Initiative, which he helped get passed by Congress in 2006.

He is a savvy operator on Capitol Hill, where he succeeded in not only funding billions of dollars in genetics research, but also pushing the passage last year of legislation that protects Americans from being genetically discriminated against by insurers and employers.

We can expect much more in the way of big projects that link different disciplines and institutes at the NIH--and possibly a reorganization of an organization that has many overlapping institutes that have grown up ad hoc over the years.

His emphasis on big might explain why Collins loves big motorcycles, including a red Harley-Davidson that he wheeled out one day a couple of years ago when I visited him at the NIH. Looking a little incongruous with his lean, tall, slightly nerdy look riding high on his hog, he took me on a ride--and proceeded to roar up and down Wisconsin Avenue in Bethesda like a big kid. Like a good scientist, he also meticulously obeyed every traffic rule, signaling turns and shoulder checking when he changed lanes. I'm sure he followed the speed limit, though I couldn't see his speedometer from the backseat.

Collins will be a fierce advocate for personalized medicine. Last year, he left the NIH after 15 years to write a book that he was unable to publish while still working for the government. He has been mum on the details, but in talking to him over the years, I suspect that it will describe the need to move more aggressively with validating genetic markers and other crucial elements of personalized medicine, while calling for a broad plan to move research and applications of medical discoveries toward a more individualized approach based on a person's own genetics and physiology.

The announcement of Collins's nomination has been long expected and was delayed in part because he has been finishing his book--his second endeavor as an author after the 2007 publication of the best-selling The Language of God, which argued in favor of theistic evolution--a process that Collins calls BioLogos. Recently, Collins cofounded the BioLogos Foundation to support the idea of fusing faith and science.

He has strong opinions about how to organize scientific endeavors, leaning toward an open exchange of data and information and less toward commercialization--a point that he has made repeatedly since fending off efforts to privatize the results of the Human Genome Project, which he headed up in the 1990s. Yet he has been careful in recent years to balance the need to promote accuracy and validation of genetic testing with a desire to promote commercial endeavors such as 23andMe and deCodeme--companies that offer the direct-to-consumer genetic testing for dozens of diseases and traits.

Though critical of the accuracy of some of these tests, Collins believes that they will be useful in the long run. Under a Collins directorate, we could see an accelerated effort to standardize and regulate these companies, either voluntarily or, if that fails, through mandatory rules.

Francis Collins has been known to make enemies. He still bristles when the rivalry between him and Craig Venter, his bitter adversary during the race to sequence the human genome in the 1990s, is brought up. Other rivals from his past also remember that the young Collins was willing to aggressively outmaneuver rivals to get ahead.

"I have to be honest about my own personality," Collins said. "I am competitive. I find it particularly exciting as a scientist to get at something that hasn't been done before. It's an incredible downer to get scooped. This is human nature."

When I sent Collins the profile that I wrote, with the allusion to St. Paul--which appears in my 2006 book Masterminds: Genius, DNA and the Quest to Rewrite Life--I was sure that he would be annoyed. But he wasn't. He found it amusing, signing an e-mail soon after as coming from "Francis, aka St. Paul."