For Immediate Release: February 18, 2014
Providence College Biology Professor and Students Analyze YouTube Videos of Flying, Swimming Animals to Define Universal Rules for Bending
Biologist, Students Have Paper Published in International Journal
Providence, R.I. – Dr. John H. Costello, professor of biology at Providence College, along with a group of current and former PC students, have had their research paper, “Bending rules for animal propulsion” published in Nature Communications, an international online journal.
The paper’s focus is on the way in which animals bend their fins and wings which, in turn, is believed to contribute to the efficiency of their movements. It has been suggested that recreating this movement artificially could, in theory, improve proficiency of swimming and flight outside of the animal kingdom.
About three years ago, Costello and Dr. Sean P. Colin ’93, associate professor of environmental science at Roger Williams University in Bristol, R.I., who work together at the Marine Biological Laboratory in Woods Hole, Mass., set out with their students to measure how flexible these animal propulsive structures are, and where they bend.
Dr. John H. Costello
Seven of the paper’s nine authors are PC alumni or researchers, including Wesley T. Beaulieu ’09, a doctoral candidate in biology at Indiana University who is also working on a master’s degree in statistics there. He contributed analysis of phylogenetic signaling. Eric Cathcart ’12, Nathan Johnson ’12, and Gregory Tirrell ’11 were all researchers as undergraduates.
Under Costello’s direction, the students searched through YouTube and other Internet video hubs (which served as research databases) for animals in motion, such as fruit flies flying through the air or humpback whales swimming in the ocean, and analyzed the footage to find universal bending patterns for animal propulsion.
The students sorted through hundreds of videos until they found several examples from 59 different species that span the animal kingdom — insects, bats, birds, fish, and molluscs. The videos had to meet specific criteria. For example, birds had to be facing directly into the camera, fish required a bird’s eye view, and whales or dolphins had to be viewed from the side. They also had to be moving at a steady speed, rather than taking off or landing.
Students then extracted individual frames from the selections and used image analysis software to measure the bending.
Despite the differences in the animals, they found similarities. The wings of a monarch butterfly bend in a similar location and at an angle similar to the tail of a bottlenose dolphin. This is true despite the fact that flying insects have no muscles in their wings, unlike the other animals studied. And it didn’t matter whether they were flying through the air or swimming in water.
The results suggest that all these different animal groups arrived at similar bending patterns through convergent evolution.
“What is it about the way they bend that is advantageous or optimal?” Costello said. “With colleagues, we’re testing those kinds of ideas and analyzing in detail.”
By recognizing these patterns, “we should be able to distinguish the mechanical basis for the biological optimum that we’re seeing,” he said. Those principles can then be incorporated into things like vehicle design.
“Animals have evolved within their lineages,” Costello said. “We hope we can get there in a few years and shortcut about 300 million years of evolution.”