Evolution Through Eating

University of British Columbia biologist captures prestigious Canadian research prize

Ottawa, Ontario, March 11, 2004 – “If you're interested in studying the really huge transitions in evolution, you really need to look at the microbial world, because that's where all the action was,” says Dr. Patrick Keeling, a Canadian Institute for Advanced Research scholar at the University of British Columbia.

The notion that large-scale evolutionary change occurs through gradual adaptations is part of biology's bread and butter. Animals and plants don't suddenly alter fundamental characteristics from one generation to the next. There aren't big genetic jumps. Certainly not burps. Or are there?

Dr. Keeling is leading biologists to rethink the range of evolutionary possibilities that have shaped and continue to shape life, and he's doing it through the detailed study of some of the world's tiniest, usually overlooked, creatures: the protists.

Keeling’s internationally acclaimed work on protists today captured him an NSERC Steacie Fellowship, one of Canada’s top science and engineering honours.

The award was among six announced today by Lucienne Robillard, Minister of Industry and Minister responsible for the Economic Development Agency of Canada for the Regions of Quebec, and Dr. Tom Brzustowski, President of NSERC.

“NSERC Steacie Fellows are quickly rising to the top of their fields while providing role models for younger scientists and engineers,” said Minister Robillard. “Through their creativity and excellent research, they are helping Canada build the knowledge base needed for a 21^st century economy.”

“These awards are public recognition for outstanding scientific achievement,” said Dr. Brzustowski. “The researchers honoured today have already started their careers in an incredible way and I know that they will do great things for science in Canada.”

The diversity of protists provides an amazing avenue for studying the molecular evolution of eukaryotes, says Dr. Keeling, and the range of his research reflects this diversity. He has discovered two of only five cases in eukaryotes of deviations from the standard genetic code, the rules guiding the translation of DNA into amino acids. His lab group is also contributing to an international effort to build an accurate tree of eukaryotic life.

But what really gets Dr. Keeling excited about protists is endosymbiosis. This is the process in which one cell eats another, but rather than digesting its meal, incorporates the ingested cell into its own cellular machinery. It's literally a case of evolution by eating.

Research by Dr. Keeling and many others indicates that this is how plastids developed in early eukaryotes. Just like larger organisms, single-celled creatures have organs, called organelles, that are responsible for basic life processes, from energy conversion to reproduction. The plastids are the organelle for photosynthesis in plants and some algae, and the mitochondria, the cellular powerhouses responsible for most of the sugar metabolism in all eukaryotic cells. It's believed that both plastids have their origins in ancient eukaryotes gulping, and keeping, bacteria.

With multicellular creatures, this evolution by eating is largely relegated to our primordial past. If we eat a burger and fries, any DNA that enters our gut cells has zero chance of making it into a sperm or egg cell. But protists reproduce by dividing, so there isn't a reproductive-body barrier.

“If a protist gets a new gene, all its kids do too,” says Dr. Keeling.

So just how prevalent is this gustatory genetics? Earlier this year, Dr. Keeling reported the first evidence of widespread and substantial eukaryotic lateral gene transfer – the movement of genes from one species to another, and it appears that eating could be one mechanism.

As an NSERC Steacie Fellow, Dr. Keeling will continue to work with Bigalowiella to see if the evidence of lateral gene transfer extends across the protist's entire genome and if other organisms are similarly affected. He'll also be working with organisms that use a variant genetic code to investigate how a genome adapts to a new genetic code, and what other factors are affected by this change.

NSERC, now also known as Science and Engineering Research Canada, is a key federal agency investing in people, discovery, and innovation. It supports both basic university research through research grants, and project research through partnerships among postsecondary institutions, government and the private sector, as well as the advanced training of highly qualified people.

Contacts:

Dr. Patrick Keeling
Tel.: (604) 822-4906

Arnet Sheppard
NSERC
Tel.: (613) 995-5997
E-mail: arnet.sheppard@nserc.ca

The Prize

NSERC Steacie Fellowships are awarded to outstanding Canadian university scientists or engineers, who have earned their doctorate within the last 12 years, and whose research has already earned them an international reputation. Nominations are received by NSERC from universities across Canada and judged by a distinguished panel of independent experts. The awards include increased research funding from NSERC and payments to the universities to allow the Steacie Fellows to pursue their research full-time. They are also eligible to compete for a special Canada Foundation for Innovation Career Award. The announcement of these awards will be made later.

The six winners this year are:

• Dr. Mosto Bousmina – Université Laval
• Dr. Thomas Brabec – University of Ottawa
• Dr. George Eleftheriades – University of Toronto
• Dr. Lisa Jeffrey – University of Toronto
• Dr. Eric Hessels – York University
• Dr. Patrick Keeling – University of British Columbia

Dr. Edgar William Richard Steacie, for whom the awards are named, was a physical chemist and President of the National Research Council from 1952 to 1962. He strongly believed that:

• fundamental research is essential to the development of science;
• the individual is key to research, and individual ideas are ultimately responsible for important advances in science;
• there are no national boundaries in science; and
• complete freedom is required for creative work.

Dr. Steacie felt that promising young scientists are our greatest asset and should be given every opportunity to develop their own ideas. Through the NSERC Steacie Fellowships, his philosophy lives on.