ft. Julie Blommaert
The Earth is full of more than 1.5 million animals that come in all different shapes. Some are winged, some walk on four or slither underground. The sheer diversity we see is what got biologist Julie Blommaert interested in how they evolve and develop — a field of science known as evo-devo.
Though physical appearances are what initially got her attention, she works on a much smaller scale: the genetics of the teeny-tiny aquatic animals called rotifers. Her subjects are so small, the females are only slightly larger than the thickest human hair. Despite this, these females look like giants compared to the even smaller males.
“They’re visible in a water sample as small dots, so I spend a lot of time at the microscope when I’m in the lab!” Julie explains.
Just as in the size difference, the females also dominate the animals’ life cycle. They normally reproduce by cloning, making a colony of identical females. Only when they’re threatened, they produce the males so they can breed with each other and shuffle their genes, improving their chance of survival.
Interestingly, each individual rotifer may have a larger or smaller genome; essentially having more or less DNA even compared to their colony mates. The difference contained in the DNA within rotifers can be more drastic than between different animal species.
In her research, Julie tries to understand which kinds of DNA are duplicated in individuals that have a larger genome. Afterward, she can start to figure out where the extra bits come from and how this affects the animal. This kind of research allows future researchers to compare the relationship between an animal’s evolutionary history and their genome size.
Despite the minuscule scale of her work, she doesn’t forget how quirky her subjects look.
“They’re often called “wheel animals” — and their German name literally means that — because the cilia on their heads beat back and forth so fast that it looks like a spinning wheel.”
“I thought they were kind of cute and weird, so when my first supervisor mentioned a project with rotifers, I jumped at the chance!“
Julie Blommaert is a PhD student studying evolutionary genomics at the University of Innsbruck. Get to know Julie and her genomics work, canoe polo, and her pet rat.