Down to the DNA

Ford Doolittle admits he enjoys shaking things up.

“I like to make trouble,” he says with a laugh. “So I think I do deliberately seek out ways to explain things differently.”

Explaining things differently has been a common theme in a 40-year career that has rewritten our understanding of DNA and evolutionary biology several times over. Today, that career was celebrated by the Natural Sciences and Engineering Research Council (NSERC) of Canada, which announced that Dr. Doolittle is receiving its highest honour: the Gerhard Herzberg Canada Gold Medal for Science and Engineering.

The Herzberg Medal recognizes research contributions characterized by both excellence and influence. Named after Canada's 1971 Nobel Prize winner in Chemistry, the award includes a $1 million research grant.  

“It's very gratifying,” says Dr. Doolittle, professor emeritus in the Department of Biochemistry and Molecular Biology in Dal's Faculty of Medicine.

“It's an endorsement of what I've done and what I'm still doing, and it will encourage me to continue doing it for a while. It will allow me to get more deeply into some of the questions I've been interested in for a long time, both philosophically and computationally.”

A revolutionary career

Dr. Doolittle is one of the world's top molecular geneticists, with more than 270 studies to his name — many of which have forced the scientific community to fundamentally re-evaluate long-held beliefs about how DNA works.

It was like that from the very start of his career. His lab's earliest work in the 1970s confirmed the then-controversial “endosymbiont hypothesis” for the origin of chloroplasts, proving that they were once free-living bacteria that now serve evolutionary interests within their hosts.

The reaction to that research paled in comparison, though, to his work on what became known as “selfish DNA” in the 1980s. Dr. Doolittle proposed that the majority of the DNA in complex organisms such as humans is essentially parasitic: natural selection working within the genome to favour “selfish” DNA elements that can replicate preferentially.

“That was a very radical notion at the time,” he says, explaining that the theory sparked waves of research around the world to test it. “People thought that all DNA had a function, and people still do; it's an ongoing debate that keeps cropping up. Now, I think many people have accepted at least, in principle, that at least some of the genome is parasitic in nature.”

It wouldn't be the last time his work was controversial. He once again sparked debate and criticism for his 1999 study on a process called lateral gene transfer, a method of gene-swapping that's common among tiny life forms like bacteria. He became convinced that this was the driving force in early evolution, and that this meant that Darwin's long-standing evolutionary tree model failed to account for two-thirds of the life on earth.

Now, 15 years later, lateral gene transfer is accepted as one of the major forces driving microbial genome evolution, including the spread of antibiotic resistance and the origin of new pathogens. Much of Dr. Doolittle's work in the past decade has been testing this notion in more detail, using bioinformatics and metagenomics (sequencing all the DNA of the community of organisms sharing a common environment).

A passion for science

Dr. Doolittle has received numerous awards and honours throughout his career, including the Award of Excellence from the Genetics Society of Canada. He is a Fellow of the Royal Society of Canada and a member of the U.S. National Academy of Sciences.

Currently, he's the senior member of one of seven Canadian teams participating in the international human microbiome project, working to understand the role that the bacteria in and on our bodies plays in health and disease. He also hopes to use the resources from the Herzberg medcal to explore, more deeply, which portions of the human genome — or any other genome for that matter — are “functional” and what it means for DNA to be functional.

In conversation, Dr. Doolittle's passion for his work is evident. He's a strong advocate for basic research and expresses some frustration that DNA isn't well understood — not just by the public, but even sometimes within his own field. He believes that understanding the building blocks of life is, in many ways, about essential self-knowledge.

“I think we see science as just one of the subjects people should learn, whereas in my mind, understanding the physical universe, including our own biology, is the first thing we should do.”