a marathoner's guide to genetics
Dr. David Smith, the geneticist, loves running marathons. He has partaken in at least seven over the last four years. Long and arduous, stretching physical, psychological and intellectual boundaries to their limit, they are as pervasive in his personal and professional lives as they are intimidating.
As a genetics professor at Western University's Department of Biology, Dr.Smith delves into the fields of biology and computer science to emerge with the tools and expertise to take decisive steps towards deciphering life's genetic design and close the gap in our understanding of its origins. Genetic blueprints are found in every organism on Earth, tightly coiled and cozily tucked within the billions of cells that make up every living thing from tiny mosquitoes, to sprawling Redwoods, and everything in between.
In Dr.Smith’s lab, the individual blueprints are translated into a string of letters, representing individual chemicals. Every organism has a distinct collection of letters that biologists refer to as the genome. "An organism's genome is like its very own instruction book containing all the necessary information for it to grow, survive and reproduce," explains Dr.Smith.
Just like letters combine in different ways to produce poems, limericks, short stories and novels, genome chemicals combine with each other in various patterns resulting in the diversity life we often take for granted. Much of Dr.Smith's work consists 'cataloguing' and 'reading' the genomes of various organisms in order to explain how they came to be 'written' in the first place.
Dr.Smith first encountered and immediately took to two "weird and eccentric" genomes during his graduate studies which would go on to become the mainstays of his research. The chloroplast and mitochondria are structures that capture energy from sunlight and food respectively and deliver it to cells. While every cell in a living organism has a complete genome, due to a biological quirk, chloroplasts and mitochondria have their own separate 'mini'-genomes.
"Mitochondrial and chloroplast genomes have highly peculiar characteristics," says Dr.Smith. It's as if they have been 'written' in a different alphabet or the instruction book is in the form of a medieval poem instead of 21st century novel.
Dr.Smith's early research findings point to neutrally evolving genomes; that the evolution of chloroplast and mitochondria is not necessarily purposeful but simply happening. This is a fairly radical finding which flies in the face of a more traditional perspective in which evolution is spurred by necessity. It is also the beginning of this marathoner’s opus to contribute to and perhaps even reshape current theories of evolution.
Just like letters combine in different ways to produce poems, limericks, short stories and novels, genome chemicals combine with each other in various patterns resulting in the diversity life we often take for granted.
One such glimpse comes from his study on the genome of a parasite called 'Polytomella'. Polytomella and its ilk cause life-threatening and financially crippling diseases in cattle. They are also responsible for devastating tropical diseases such as sleeping sickness that has increasingly been on the rise in North America due to growing global tourism and more accessible air travel. "I consider these radical genomes as moving targets," remarks Dr.Smith and continues, "with a better understanding of such genomes, we can uncover their weaknesses and design more effective drugs to combat such diseases." His work on these genomes has also enabled him to model billions of years of evolution in the efficiency of his laboratory. Not only can he tell us how have these genomes evolved but, biologically speaking, where they are headed towards.
"Who knows, some of these genomes might hold the secret to renewable sources of biofuels or help us discover medicines that can cure cancer," Dr.Smith notes. He optimistically remarks, "I am certain that if more researchers make a concerted effort to study and chart out these woefully under-explored and under-appreciated blueprints of life, such secrets will be ours for the taking." Is the finish line in sight? Not yet. All in good time.