Every Sunday when his children were small, Clarke Fraser treated them to milkshakes in Montreal's west end and then whisked them off to the "mouse room" in the biology building at McGill University. There, surrounded by files and cages, he would check on his experiments and show the children exactly what he did for a living, as a pioneering medical geneticist who was studying congenital deformities.
Plain spoken and with a penchant for off-the-cuff ditties and poems, Dr. Fraser, who died Dec. 17 at the age of 94 from what he called "chronic progressive decrepitude," believed that showing was just as important as telling, regardless of the listener's age. Dry lectures delivered in a monotone and filled with statistics were not his style. He even used a ukulele as a prop in his Intro to Genetics class, strumming it as he sang a song about genes in a voice that was mostly on-key.
Near the start of a long and much-lauded career, he discovered that cortisone given to pregnant mice caused some of their offspring to develop cleft palates, depending on the mother's and baby's genotype. The breakthrough marked the beginning of a field known as teratogenics, but for his children, those afternoons in the mouse room were subtle lessons in how both nature and nurture play roles in development. There was luck involved, to be sure, but there was also a need to work hard for what they wanted while staying true to themselves and never losing the ability to laugh, no matter what life threw their way.
"He was a great role model for living through life-changing events," said his son, Noel Fraser, an administrator at McMaster University in Hamilton. "He was so affected when he lost his parents and it was frustrating as he got older and frailer. But he always laughed and he always kept trying."
A lifelong atheist, Dr. Fraser, whose chastisement of choice ran along the gentle lines of "you dunderhead," also taught his children to believe in science and their own power to deduce what was right and wrong.
"It followed from his commitment to logical thinking," his daughter, Norah Fraser, wrote in an e-mail. "Not believing in God meant that one had to develop a sense of ethics without religion. … One of his tests for right action was, 'What would the world be like if everyone behaved that way?'"
In one paper, Dr. Fraser described his scientific life journey, which besides teratogenics included helping to develop the principles of genetic counselling, as more of a "happy gambol than a planned itinerary."
"It rambled off on false trails here, dashed after clues to new ideas there … but following new signposts as they turned up, rather than steadfastly pursuing a foreseen goal," he wrote in Of Mice and Men, an autobiographical essay published in a 2008 issue of the American Journal of Medical Genetics. "I seemed to be more attracted by genetically complex (i.e., "messy") systems and how to ask meaningful questions at the epigenetic level than by the more rigorous classical approach of counting and mapping genes."
Dr. Fraser looked at the whole picture rather than discrete pieces. While genetics itself can be like a crossword puzzle or a series of probabilities, he brought to the field an instinctual empathy that others lacked. It was because he understood that genetics wasn't black and white – but rather a crapshoot, all odds and prayers – that, unlike his contemporaries, he never told prospective parents what they should do.
"Clarke believed in choice and laid the groundwork for his patients to make them," said Charlie Scriver, a long-time friend and colleague who pioneered the field of biochemical genetics in Canada. "He told them about the gene, what was mistaken in its coding information and then, he gave them options."
Hy Waxman, a Montreal gift-wrap manufacturer who was close friends with Dr. Fraser for more than half a century, recalled that he only learned what his friend did for a living three years into their acquaintance, when he read a newspaper story about his work.
"At one point, when he was writing a book geared more for the general public, he told me he wasn't sure he would be understood," Mr. Waxman said. "I became his common man, reading a few pages at a time and commenting in my own non-medical way."
Frank Clarke Fraser was born in Norwich, Conn., on March 29, 1920, the first of Frank and Annie Fraser's two children. He inherited webbed toes from his father, which he would later speculate accounted for his love of genetics and swimming, the latter an activity he did often growing up in Jamaica, where Frank Sr. served as the Canadian trade commissioner for 10 years.
The family also spent time in Dublin and in Montreal. Most of all, though, young Clarke loved visiting his maternal grandfather's house in Bear River, N.S., which he described in Of Mice and Men as a "picturesque village on a tidal river that alternates between gleaming lake and glistening mud flat twice a day."
There, in the big white-frame house with the sweeping veranda and the row of tall maple trees, he felt at home. There always seemed to be people filling up the place: aunts, uncles, cousins and friends. Two maids sang in the kitchen as they worked, while his parents were wont to hold impromptu concerts in the parlour, his father on piano and his mother, who had done a music degree at university, singing with her soaring, clear voice.
At one point, young Clarke, a star student, and his sister, Mary, were sent from Jamaica to Bear River for a longer stint so they could attend nearby Acadia University. Faced with rules such as no cards on Sunday, no liquor in the house and having to make their own beds and mop their bedroom floors each day, it was a marked change from life on the island, where servants had catered to their every need and they could play tennis, golf and swim to their hearts' content.
At Acadia, he started the pre-med program, thinking he would follow in the footsteps of a great-uncle who used a horse and buggy to pay house calls to patients throughout Bear River and its environs. But two lectures in genetics changed the course of his life from folksy family practitioner to physician and human geneticist who would eventually work in the wards of what is now the Montreal Children's Hospital while launching a department at McGill.
Between the doctorate and the medical degree, which he received in 1950, Dr. Fraser trained as a bombardier in the Canadian Air Force, but he never saw combat before the Second World War ended.
For a man whom friends and colleagues considered even-tempered and who disliked raising his voice in anger, he loved the sense of power blasting down the runway and then soaring like an Olympian high above the world. He later wrote of the exhilaration at starting a spin, of being out of control for a few seconds that seemed like forever and then recovering. It was a feeling he would never forget – freedom, flight and fear all rolled up into a huge jolt of adrenalin.
Dr. Fraser was the Molson Professor of Human Genetics at McGill until the age of 62, when he moved for three years to St. John's to develop a similar program at Memorial University. Afterward, he went back to McGill as a professor emeritus, remaining there until his retirement in 1999 and a return to his beloved Bear River.
In 1972, Dr. Fraser divorced his first wife of 24 years, Beryl DeBlois, with whom he had four children. A few years later, he married Marilyn Preus, at the time a graduate student in genetics.
Along the way, he received honorary degrees from universities such as Acadia, Dalhousie and McGill, and a number of accolades including the William Allan Award in 1979 from the American Society of Human Genetics and, in 1999, the Prix Wilder-Penfield, a Quebec provincial prize for scientists whose research falls with the purview of biomedicine. In 1985, he was named an Officer of the Order of Canada; he was inducted into the Canadian Medical Hall of Fame in 2012.
Throughout Dr. Fraser's life, some things we immutable: tennis, squash, family dinners, fly-fishing, a Scotch each evening before dinner and, after the move back to Bear River, a Saturday night phone call to Mr. Waxman in Montreal.
"The kind of friendship we had was rare and it lasted what seemed like a lifetime," Mr. Waxman said. "It's strange that I don't hear from him on Saturdays any more."
Dr. Fraser leaves his wife, Ms. Preus; his children, Norah, Noel, Alan and Scott Fraser; and seven grandchildren.
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