Canadian who studies finches and fish wins one of science’s top prizes

As It Happens6:43Canadian who studies finches and fish wins one of science’s top prizes

Dolph Schluter is fascinated by the origins of species, whether it be the famous finches of the Galapagos or the “humble” threespine stickleback fish of British Columbia.

The University of British Columbia (UBC) zoologist has spent his career studying how new species come into existence.  Now he’s being honoured with one of science’s most prestigious awards, the Crafoord Prize in Bioscience.

“I’m still getting used to it,” Schluter, a professor of zoology at UBC’s Biodiversity Research Centre, told As It Happens host Nil Köksal.

“We all want to be recognized for the work that we do, I suppose, but … this is so far off the radar, it caught me completely off guard.”

The Royal Swedish Academy of Sciences awards the Crafoord Prize for disciplines it doesn’t consider for the Nobels, including biosciences, geosciences and mathematics. Schluter’s victory comes with a prize of about $780,000 to fund further research in his field.

“Dr. Schluter’s contributions have been vastly influential,” Ove Eriksson, chair of the prize committee for the Crafoord Prize in Biosciences, said in a UBC press release. “We regard Dr. Schluter as the leader in ecological studies of the origin of species over the last four decades.”

What finches and fish teach us about evolution

Schluter’s body of research focuses on two main themes: the origin of species and adaptive radiation, the latter of which he defines as “the rapid production of a bunch of species that are doing different things [and] exploiting the environment in different ways.”

The classic example, he says, is Charles Darwin’s Galapagos finches — a group of more than a dozen birds on the Galapagos Islands that are believed to have evolved from a single species.

Despite their common origin, the birds have a remarkable variance in traits, which partly inspired Darwin’s foundational theory of evolution.

“Across the tree of life, it’s estimated that to get two new species that have one common ancestor takes, on average, about two million years,” Schluter said. “In the Galapagos finches, that process has been sped up. It’s on the order of 100,000 years.”

Schluter has studied the evolution of Galapagos finches. (Shutterstock)

Some of Schluter’s earliest work looked into exactly how that famous example of evolution played out.

While studying the finches, Schluter found the differences in beaks was often more pronounced between species that lived on the same island than it was between finches that lived on different islands.

That means the finches evolved, in part, in response to competitive interaction, rather than simply through geographic isolation. 

Beak size plays an important role in determining what kind of seeds the birds can eat. And birds that didn’t have to compete over the same food source had a better chance of surviving and breeding. 

This is what’s known as speciation — evolution through natural selection, rather than by accumulation of chance mutations.

“Dolph Schluter’s studies allowed him to prove that, in the right conditions, Darwin’s well-founded thoughts about speciation really do occur in nature,” Kerstin Johannesson, a professor of marine ecology and member of the Royal Swedish Academy of Sciences, said in a press release. 

A gray fish with a green and yellow back and two spiky obtrusions on its back.
The threespine stickleback is a marine fish that has colonized several lakes in B.C., creating several branches of evolution. (Justas in the wilderness/Shutterstock)

These days, Schluter has turned his attention from feathers to scales.

His current research revolves around the threespine stickleback, a marine fish that has repeatedly colonized freshwater lakes in B.C., thereby creating different branches of evolution.

Each of the B.C. lakes where sticklebacks are found have two species of the fish each, Schluter said. And in each case, they are found nowhere else in the world.

But what makes them so interesting for Schluter is that the lakes themselves are only about 10,000 to 15,000 years old — the blink of an eye, in evolutionary terms. That means these fish are “among the youngest species on Earth in anything.”

“If you want to study the origin of species, it’s best to catch it as it’s happening. And, you know, this is possible with these fish because it’s all happened so rapidly, so recently.”

A man tosses a small cage into a lake.
Schluter conducts research on threespine sticklebacks in B.C. (Marius Roesti/crafoordprize.se)

Much like the finches before them, the freshwater fish have acquired different traits than their marine counterparts.

And as the generations pass, further differences are developing between the fish living in the same lakes. Some have evolved to live exclusively at the bottom of the lake, and others closer to the surface.

“We’ve managed to learn a great deal about the origin of species just from working on this fish,” Schluter said.