In a new study that would have made Rudyard Kipling proud, a UTSC graduate student has provided the most definitive answer yet to the curious question, “How did flying fish get their wings?”
Eric Lewallen, a PhD student in professor Nathan Lovejoy’s ecology and evolutionary biology lab at UTSC, is the lead author on the first molecular study of genetic relatedness among species of flying fish. Appearing in the Biological Journal of the Linnean Society, Lewallen’s paper confirms what scientists have long hypothesized—that the wide variety of “flying” strategies found in fish around the world are all the result of a single evolutionary chain of events.
“Our results show that flying fish are monophyletic, which means they all share a common ancestor,” said Lewallen. “This suggests that true gliding behavior in fish evolved just once, and all the modifications we see today can be traced back to that one event.”
There are approximately 50 species of flying fish to be found in the tropical and subtropical regions of the Pacific, Atlantic and Indian oceans. Their “wings” are really just enlarged fins, accompanied by specialized muscles, which together allow them to burst out of the water and glide above the ocean surface for short periods of time.
Some species have two pectoral wings, while others have two pectoral and two pelvic wings. The two-winged species can exit the water quickly and usually glide in a straight line. Four-winged species can glide for hundreds of metres at a time and can even manouevre in mid-air to change direction.
Scientists believe fish evolved various gliding abilities in order to evade specific predators such as tunas, dolphins and seabirds.
Over the last few years, Lewallen has had his fair share of adventures while collecting his fish specimens. Due to the high cost of conducting research on the high seas, he has often worked aboard boats operated by the National Oceanic and Atmospheric Administration (NOAA) in return for the opportunity to collect specimens. By day, he would work as an independent marine mammal observer for NOAA studies. By night, he would catch his flying fishes using spotlights and dipnets.
“The shocking part,” said Lewallen, “is that flying fishes are so abundant—they’re found in every major tropical ocean—yet many basic questions regarding their ecology and evolution remain unanswered.” Lewallen’s paper, which will serve as the first chapter of his PhD dissertation at UTSC, provides an exciting foundation for future studies involving open ocean organisms.
“There are many complex questions I would like to address regarding these creatures and their habitats,” he said. “But we’ve got to lay some of the groundwork first.”
Lewallen’s work provides further evidence of UTSC’s emerging leadership in the field of conservation biology.
Noted Professor Lovejoy, “The great success of Eric’s study is that it highlights UTSC’s growing strength in field biology, graduate research and internationally collaborative science.”
University of Toronto
Thursday, January 13, 2011
1/13/2011 04:38:00 PM Publicado por Alquimia