When the Royal Ontario Museum’s curator of invertebrate paleontology needs to learn more about a 500-million–year-old fossil, he turns to UWindsor’s Sharon Lackie.
Lackie operates the scanning electron microscope at the Great Lakes Institute for Environmental Research. On even the most routine of days, Lackie helps researchers make breakthroughs in chemistry, biology, physics, engineering, environmental science, geology, and more.
But recently, she was featured along with Jean Bernard-Caron of the Royal Ontario Museum in a yet-to-be-aired international episode of the CBC science documentary series, The Nature of Things, about a discovery that has changed our understanding of prehistoric life.
The episode features the planet’s first animals — creatures that perished in an underwater mudslide more than half a billion years ago and remain buried in the Rocky Mountains’ Burgess Shale. In the episode, Dr. Bernard-Caron brings a sample to Lackie for elemental analysis, discovering that the tiny white spots on a fossil were actually eggs the creature was carefully transporting under its shell.
The arthropod, called Waptia, is the earliest creature ever discovered to have displayed brood care. In her 12 years of analyzing fossils for the museum, Lackie has also helped Bernard-Caron discover the first animal with a spinal cord, and, by analyzing the eyes on another creature, establishing that mollusks existed much earlier than previously believed.
“This is a very interesting job,” said Lackie. “I feel very lucky.”
As its name suggests, a scanning electron microscope uses electrons to create an image as they hit the surface of the sample. It has a camera so the user can see the sample as it sits in the chamber, and x-rays for elemental analysis.
The microscope generates electrons by passing electricity through a filament, not unlike the ones contained in light bulbs, except that the one in this instrument costs $10,000 to replace if damaged.
The electrons go down into a cylinder through a vacuum to prevent them from scattering. As the electrons hit the surface of a sample, they generate an image that is reproduced on a computer screen. The GLIER microscope can magnify specimens up to 250,000 times.
It’s an indispensable tool for paleontologists and inventors because samples can be analyzed in their natural state. Other electron microscopes require samples to be first coated in a conductive material like gold or carbon.
The instrument can identify every element contained in a sample, with the exception of hydrogen, helium and lithium which are too light to detect. It generates a graph with each element represented, and a map representing each element by a different colour.
“We can determine the composition of anything we look at,” Lackie said, demonstrating how the microscope can be programmed to scan a sample, area by area, pixel by pixel.
Lackie said that’s how she often handles fossils hand-delivered to her by workers from the museum. She will put the fossil in the chamber on a Friday and allow the microscope to run all weekend.
Lackie, who holds a Master’s degree in plant science as well as a Bachelor of Education, trains researchers on how to use the microscope and schedules their time, usually booked three weeks in advance.
It’s used for on-campus research as well as by industry, and is especially useful for scientists developing new materials on a nanoscale.
“Often they can’t see if their work has succeeded until they come here.”
Lackie said she feels privileged to contribute to new discovery.
“I could be looking at bacteria in the morning and car parts in the afternoon,” she said. Then there are the odd 500-million–year-old fossils thrown in for good measure.
“It’s amazing to me.”