On September 27, the sixth cohort of graduates from the Museum’s Richard Gilder Graduate School—the first Ph.D.-degree-granting program for any museum in the Western Hemisphere—will receive Doctor of Philosophy degrees in Comparative Biology at a commencement ceremony in the Milstein Hall of Ocean Life. We’re profiling the soon-to-be Ph.D.s.
As a boy growing up in Cranbury, New Jersey, Michael Tessler relished weekend excursions with his family to the lush Longwood Gardens in Kennett Square, Pennsylvania, the Academy of Natural Sciences in Philadelphia (today part of Drexel University), and the American Museum of Natural History—where, to this day, he finds the dioramas thrilling. “That doesn’t go away,” he says.
He also fondly recalls trips to an aunt’s home in the Catskills where he would delight in jumping off the deck into a lake full of tadpoles and turtles. Tessler turned his curiosity into a B.S. degree in natural history from Sterling College in Craftsbury Common, Vermont, and a Master’s degree in biology from Fordham University, where he studied the ecology of mosses.
“I still want to know about everything I see in the woods, and under the rocks I turn over in the river,” says Tessler.
Which brings us to leeches. Intrigued by a book he’d read about blood feeders and his own first-hand experience of terrestrial leeches during a trip to Tasmania in 2012, he jumped at the chance to work with Mark Siddall, curator in the Museum’s Division of Invertebrate Zoology and a renowned parasitologist. When Tessler matriculated at the Richard Gilder Graduate School in 2013, Dr. Siddall became his advisor.
In 2015, Tessler accompanied Siddall on a Constantine S. Niarchos Expedition to Cambodia, where they searched for leeches whose gut contents could help determine which rarely observed mammals were being fed upon by the leeches, documenting their presence in a particular area. (Watch the video below on more about the expedition and on how leeches can provide scientists with clues crucial to conservation.)
The following year, Tessler, Siddall and other museum colleagues described a new species, Chtonobdella tanae (named in honor of the novelist Amy Tan)—the first-ever description of an extant soft-bodied species to use the technology of computed tomography (CT) scanning.
Tessler’s time at Gilder was also marked by working with students at all levels, including college biologists through the Museum’s NSF-funded Research Experience for Undergraduates, high school students through the Science Research Mentoring Program, and even third graders in the Museum’s Science and Nature program. “I got to talk to the kids who were like me when I was growing up,” he says.
This month, Tessler began working as a postdoctoral fellow with the NYC plant genomics consortium through NYU and the Museum. This research—on the evolutionary biology of flowering plants—brings him back to botany, an area he concentrated on while earning his Master’s degree. But he hasn’t abandoned leeches, either, and there are several projects with Siddall yet to be published.
“You learn a lot by switching around,” says Tessler. “Animals do things plants don’t do. Leeches do things dinosaurs don’t do. You get a pretty good picture of biodiversity when looking at a lot of organisms, which is what I’m interested in.”