Features
Life on Earth
Biologist studies how planet’s array of life came to be
BY ANDREW VOWLES
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| "We have a moral obligation to consider biodiversity," says Prof. Sarah Adamowicz. Photo by Martin Schwalbe |
She grew up exploring the woods and tidal pools around Saint Andrews, N.B.
Now, as a recent arrival in the Department of Integrative Biology, Prof. Sarah Adamowicz brings a grown-up perspective to learning about the natural world, notably through her evolutionary and DNA bar-coding work with the Biodiversity Institute of Ontario (BIO). But part of her is still that youngster trekking with her sister and their biology teacher dad, uncovering life around their maritime home.
“I find biodiversity fascinating,” says Adamowicz, who will help teach this year’s Arctic ecology field course in Churchill, Man.
These days, that childhood curiosity is tempered by serious considerations. Understanding the natural world around us — and how it came to be the way it is — holds important lessons for conservation, agriculture, food safety, health, the environment and the economy, she says.
There’s even a moral imperative at work here. Curiosity might impel you to flip over a rock in one of those seaside tidal pools. But Adamowicz says we’re responsible in a way for whatever tiny creatures we find living under there.
“We have a moral obligation to consider biodiversity. We’re not the only beings to live here.”
She’s interested in big-picture questions about living things. For instance, just how many species are there on the Earth? (Estimates range from 10 million to 100 million.) Why are some kinds of organisms more diverse than others? What affects how quickly new species develop? And what are the large-scale patterns that have shaped life on this planet?
One likely answer to that last question came in a 2008 paper co-authored by Adamowicz in the Proceedings of the National Academy of Sciences. She was a post-doc at the University of Waterloo last spring when the paper pointing to the so-called first “rule” of evolution appeared. That study was co-written by colleagues at the University of Bath and at Imperial College London, where Adamowicz had completed her PhD two years earlier.
Starting with fossil crustaceans from more than 500 million years ago and working forward to today’s lobsters and crabs, the researchers found evidence that these creatures evolve from a simpler, repetitive body plan to more complex forms, as appendages with various structures and functions sprout from different body segments.
That conclusion might seem self-evident to some observers, but Adamowicz says it’s important to back up assumptions with scientific evidence. For most modular creatures they looked at, the same general rule applies: things tend to evolve greater structural complexity, not less.
That applies across various branches of the crustacean family tree, she says. Evoking a metaphor made popular by the late evolutionary biologist Stephen Jay Gould, she says rewinding and replaying the tape of life would lead to different branches of animals, but the same broad pattern — greater complexity — shows up.
Last summer, she joined Guelph as a post-doc with the BIO, helping to grow that institute’s catalogue of DNA bar codes used to identify organisms. She was appointed a faculty member early this year.
“The allure of Guelph was quite strong,” says Adamowicz, who completed a master’s degree here in 2002 with integrative biology professor Paul Hebert, who now heads the BIO. “It’s a great opportunity to collaborate in the largest biodiversity project yet undertaken.”
It was during her master’s studies that she met another grad student, Ryan Gregory, who returned to Guelph as a faculty member in 2005. They were married in 2008.
Adamowicz is especially interested in aquatic invertebrates and in how biodiversity and distribution of organisms have evolved. Those interests take her in two opposite directions.
She’s looked at relationships among amphipods, a crustacean living in Bolivia and Peru’s Lake Titicaca. Not only is this the world’s highest large lake, but it’s also one of a few “ancient” lakes formed well before the Ice Age.
This year, she also visited Argentina with Guelph colleagues to hold a bar-coding workshop for South American biologists. Glancing at a Spanish-language dictionary on her desk, she recalls her undergraduate years at Dalhousie University.
“I decided to take Spanish for fun, but it’s been extraordinarily valuable in promoting collaborations.”
As co-leader of the polar bar-code working group, she visited Churchill with a team last summer to collect freshwater and marine invertebrates, as well as land insects such as crane flies. She says trying to catalogue biodiversity at that particular site is daunting, illustrating the larger challenge of nailing down the number of species on Earth.
“We are so far from understanding the true level of biodiversity, but we are getting closer to answers than ever before.”