Many of us, when we see an insect, will squish it.
Millions of years ago, it was just about the same story, except, as Dr. Bruce Archibald explained, they were squished by soft sediments that formed into rock and so achieved immortality, forever being preserved as a fossil.
As have many other animals and plants, Archibald noted — his specialty just happens to be insects.
A researcher with Simon Fraser University, Archibald was in town last week discussing fossils, particularly the ones found at Driftwood Canyon Provincial Park. The ones in Driftwood are from the Eocene period, 54.8 million years ago.
“What a wonderful resource you have in your backyard,” Archibald said, who’s been up here numerous times since 2000.
Now a shale-filled hill, once upon a time the park was actually a lake, Archibald said, with a climate that supported spruce, pine, hemlock, beech, chestnut, oak, magnolia and palm trees.
“The climate had low seasonality,” Archibald said, explaining how a palm tree could thrive in what is now Northwest B.C. “So no frost.”
They know this because of the evidence left behind: the fossils. Displaying numerous photos of specimens depicting some of the flora described above, these provide an excellent picture of how life was all those years ago.
Researchers such as himself look to fossils to explain two phenomena, Archibald said. First, to look for links between species here and Asia, and second, to study biodiversity in these regions.
For example, why is there a greater diversity in the tropics than Tofino? The answer, found by looking at fossil records from different areas, is that biodiversity is best supported by a steady climate, not one that has a wide seasonality. So the tropics and an area like Driftwood, that had a cooler temperature but one more consistent, will have a greater number of species than one like Tofino where there’s such a range of temperatures.
“And there’s still a lot we don’t know,” Archibald said.
He ended by telling a story that we do know: the one of the green lacewing. Green lacewings are very good for one’s garden, Archibald remarked, as they mostly eat aphids and are predominantly active in the evening hours. Two of the four groups of green lacewing, the Nothochrysinae and Chrysopinae, still exist today. However, the Nothochrysinae are limited in numbers while the Chrysopinae are flourishing.
The reason: the Nothochrysinae didn’t adapt very well to our cooler temperatures (compared to Eocene times) while Chrysopinae can survive in a much more diverse range of temperatures.
But fossils add another dimension to the story, one that ties their populations with bats. Bats were first found in the early Eocene period and their populations exploded, becoming a very successful group quickly.
Fossil Chrysopinae specimens show a bulbous vein on one of their four wings, a feature missing from the Nothochrysinae. A very important feature, Archibald said, as that bulbous vein is the “ears” of the Chrysopinae that can detect the echo-locating screech of the bats, allowing them to drop suddenly, that much more effective at avoiding predation.
If they can learn all of that by examining one of the high quality fossils found here in the Bulkley Valley, imagine all the other wealth of knowledge available for discovery, he said.
“These are the things that we’re working on that Driftwood helps us understand,” Archibald said.