30 years of finches

They met in 1960 at the University of British Columbia in Vancouver. More than 45 years later, Peter and Rosemary Grant were married — and back in Vancouver for a conference in their honor — when they received word that one million Swiss francs would be coming their way.

The Grants, who both teach in the Department of Ecology and Evolutionary Biology, had been jointly awarded a Balzan Prize — worth about $800,000 — for their 30 years of cumulative research on the evolution of Darwin's finches on the Galápagos Islands.

"It was a complete surprise," said Rosemary Grant, a Senior Research Biologist in the department. Her husband, the Class of 1877 Professor of Zoology, called it "a surprise prize!"

Every year, two Balzan Prizes are awarded in the humanities and two in the sciences. Within these categories, the particular fields for which the prizes are given rotate annually; the Grants won in the category of population biology.

"The work of the Grants has had a seminal influence in the fields of population biology, evolution and ecology," according to a statement from the International Balzan Foundation. "It is generally regarded as the most significant study of evolutionary change in the field that has been carried out in the last 30 years."

When they began their research three decades ago, the Grants sought to answer three questions: Do members of different species compete with each other for food? If so, what might the evolutionary significance of that be? How are species formed, and why are some populations so much more variable than others? The Grants looked to Darwin's finches for answers.

"It's a group of species that has evolved from a common ancestor in the Galápagos fairly recently and rapidly," making them well-suited to research, Peter Grant said.

The Grants' research has improved scientists' understanding of evolutionary patterns and mechanisms.

"The most exciting single discovery is that natural selection occurs strongly and repeatedly in environments like the Galápagos, where the climate fluctuates from very wet to very dry," Peter said.

They also discovered the importance of birds' songs, which are unique to each species.

"When an individual misimprints, that is, learns another species' song during the short sensitive period for learning, this individual will mate according to song type and not [physical appearance], leading to rare cases of hybridization," Rosemary said in an email.

The Grants became interested in science long before they met.

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"One of my first, earliest memories is chasing butterflies," Peter said. "Why I was the one chasing butterflies while everyone else was playing games, I don't know."

His pastime eventually gave way to studying botany in high school and zoology at the University of Cambridge. He would later earn a Ph.D. at the University of British Columbia and complete a postdoctoral fellowship at Yale.

Meanwhile, Rosemary studied genetics and zoology at the University of Edinburgh and earned her Ph.D. at Uppsala University in Sweden. In between, she lectured at the University of British Columbia, where she met her future husband.

The Grants have worked together on all of the Galápagos Islands, but conducted their most detailed research on Genovesa Island and Isla Daphne Major, which is the top of a 350-foot high volcano. When doing field research, the Grants live in a tent — Daphne is so small it can fit only one of them — for three or four months at a time.

On the Galápagos, the Grants' day begins at 5:30 a.m., before dawn, when they set up mist nets to capture awakening birds. They spend the morning weighing and measuring the birds, collecting blood for DNA analysis, locating and examining nests and the eggs or nestlings within. After an afternoon of vegetation analysis and insect sampling in the heat of the equator-centered islands, they go to bed in their tent at 7:30 p.m.

The Grants make sure to preserve the finches' environment, a factor that partly determines their lifestyle while on the Galápagos. They buy all of their food in Ecuador and freeze dry food to eliminate foreign insects. Most fresh fruit is off-limits, because seeds that are not native to the islands would disrupt the environment.

"Our diet is very limited. It's not unhealthy, but it's very limited," Rosemary said.

When in Princeton, they eat a lot of the fresh fruit they miss on the islands and are glad to bathe, since on the islands they bring all of their drinking water and wash in the sea.

"But we enjoy being on the islands very much," Rosemary said. "I think we both really enjoy the contrasting lifestyles."

For the past several years, the Grants have collaborated with Clifford Tabin, Professor of Genetics at Harvard Medical School, and Arkhat Abzhanov, an Instructor in the Department of Oral and Developmental Biology at the Harvard School of Dental Medicine.

While the Grants focus on evolutionary biology, the Harvard scientists examine the genetic data they gather, a combination that allows the researchers to explore the genetic mechanisms behind the evolutionary changes that the Grants discover in the field.

"At Harvard we have identified one of the important genes responsible for the development of beaks of different sizes and shapes," Rosemary said.

Abzhanov — who now collects his own data in the Galápagos using the field techniques the Grants have taught him — is enthusiastic about the researchers' joint efforts.

"I found the collaboration was great," Abzhanov said. "They're very interested in what they do."

Abzhanov commended the Grants' study as an important link in the chain of evolutionary knowledge, helping to explain the progression of traits over time.

"You can find plenty of evidence how it works, so that's exactly what they did," Abzhanov said. "I think that's a very big contribution."

The Grants have worked in the Department of Ecology and Evolutionary Biology since 1985, nestled in book-filled, adjoining offices with a connecting door that is almost always open. While on campus, the Grants teach courses, write articles and analyze statistics. They jointly published "Evolutionary Dynamics of a Natural Population: The Large Cactus Finch of the Galápagos," which won the Wildlife Publication Award of the Wildlife Society in 1991, and Peter published "Ecology and Evolution of Darwin's Finches" in 1986.

The two were also the subject of a 1995 book, "The Beak of the Finch: A Story of Evolution in our Time."

Research is not the only thing that interests the Grants, though; the pair also enjoys the mentor aspect of their work.

"I think a very big reward for both of us ... is in teaching, to see the intellectual growth of students," Peter said.

Martin Wikelski, Associate Professor of Ecology and Evolutionary Biology, said the Grants largely influenced his decision to come to the University.

"Do you know Santa Claus? That's pretty much how Peter is. They're just both fantastic personalities, and they have to be very persistent and very innovative in their research," Wikelski said. "What they have done is the best you can ever do in a small setting."

Wikelski described the Grants' penetrating influence not only on the field of evolutionary biology, but also on the mindsets of young scientists.

"They always encourage you to think about — sort of to really think problems through, so you're not content with the superficial answer," Wikelski said. "They really induce young researchers to think independently and address these deep evolutionary problems."

Their award will help them do just that; half of the Balzan Prize money must be used to fund young scientists.

"We hope that it will give young people an opportunity to extend their research," Rosemary said.

" — and possibly take new directions," her husband finished.