A UBC Okanagan Biology student has won the Governor General’s Gold medal award for her research into the DNA of near extinct tortoises.
Evelyn Johnson graduated yesterday with her PhD.
The Governor General Gold Medal is presented annually to the graduate student with the highest academic achievement.
Johnson achieve an “A” in all her coursework and conducted what’s been termed remarkable research in genomics.
Jensen and and her supervising professor Michael Russello travelled to the Galapagos Islands to study a new generation of giant tortoises-once a species considered extinct in the wild.
Through her work, she was able to compare and analyze the genetic makeup of different generations of Galapagos giant tortoises on Pinzón Island dating back to 1906.
Russello explains that whalers, pirates and explorers had used the Pinzón Island tortoises as a fresh meat supply, decimating the population.
To make matters worse, the sailors inadvertently introduced a species of black rats to the island-the invasive rats lived on the tortoise eggs, and the survival rate of the tortoise plummeted.
“At one time there were thousands of tortoises and they were easy to hunt,” says Russello. “The species was heavily harvested and black rats thrived by attacking the nests and eating the eggs. It got to the point where there were about a hundred or so of these tortoises left on the island and they weren’t repopulating. They were indeed a population of the living dead.”
More than 50 years ago, scientists introduced a headstart management plan; eggs were transported to a nearby island to hatch and grow in captivity before being repatriated to their home island.
In 2012 the rats were eradicated from the island and by 2014, wild-hatched young tortoises were surviving on the island.
Evelyn Jensen says “Written in the genome of every individual are not just instructions for building the organism, but also the history of its ancestors. When populations of individuals are analyzed together, their DNA can tell an even larger story of how the population has changed through time.”
By pairing historical DNA analysis, and the DNA of Pinzón Galapagos giant tortoises sampled pre- and post-decline, she was able to show that the historical sample provided a valuable benchmark for evaluating the head-start program.
The research was recently published in the Journal of Heredity.
Jensen’s research revealed that Pinzón tortoises have retained a remarkable amount of genetic variation despite their near extinction, which, she says, further demonstrates the effectiveness of the conservation intervention in this system.
She is now developing baseline population genomic information about polar bear populations in Canada, and creating new biomarker toolkit that will be used to monitor polar bears from non-invasively collected scat samples.