A Montana State University scientist is part of an international team of beetle experts that has provided a glimpse of life before dinosaurs and assembled a major new view of one of the largest branches of the “tree of life.”
Scouring the world for 10 years, MSU entomologist Michael Ivie and the other scientists collected the DNA of both common and rare beetles in their quest to unravel some of the mysteries behind the development of the animals.
The entomologists examined a pool of DNA data from nearly 400 carefully selected species that represented all of the major lineages of this diverse group of insects. Their findings will be published in the October issue of the scientific journal Systematic Entomology and are currently available online through the publication’s “early view” feature.
Combining the most robust and inclusive beetle family tree ever assembled with a fossil-calibrated timescale revealed both pattern and age for the tree and its many branches, Ivie said.
“The tree of life refers to an effort to understand the interrelated history of all life on Earth,” Ivie said. “The group assembled to collaborate on this project was unprecedented, representing a truly global effort of an all-star team. The results are simply spectacular as a result.”
Duane D. McKenna, assistant professor of biological sciences at the University of Memphis and the paper’s leader author, said the work reveals new insights into 300 million years of beetle evolution.
“Low extinction rates, protected wings and ancient interactions with plants, fungi and microorganisms appear to be the main keys to their success,” McKenna said.
The research provides many hypotheses to pursue in future studies, particularly exploring the structural adaptations associated with beetles' diverse ecological roles, Ivie added.
Co-author Brian Farrell, a professor of organismic and evolutionary biology at Harvard University, initiated the project in 2005 along with David Maddison, professor of integrative biology at Oregon State University.
“The fact that beetles have been the most dominant group of terrestrial animals since the Jurassic is under-appreciated largely because of their small bodies,” Farrell said. “If they were the size of Volkswagens, Steven Spielberg would not have had to make those movies…. Nevertheless, by simple virtue of their hard protective wing covers, beetles have been able to extend their physical access to new food sources throughout the diversification of an ever-more physically and biologically complex environment."
Maddison noted that the knowledge gained about the shape of the beetle tree of life will be critical for understanding the origin of the myriad forms of beetles.
“The branches of the tree are the conduits along which genes have flowed over millions of years,” Maddison said. “Its shape provides the vital roadmap that can help us understand the patterns and processes of beetle diversification.”
Beetles arose long before dinosaurs in the Permian Period and alongside the very first terrestrial vertebrates - ancestors of today's amphibians, lizards, turtles, birds and mammals. Beetles also survived the mass extinctions at the end of the Permian Period and began their rapid rise to the stunning diversity of today, with more than 350,000 known species, Ivie said.
Already extremely diverse by the time of the next major extinction at the Cretaceous-Paleogene boundary, which also saw the demise of the dinosaurs, beetles successfully weathered that event with hundreds of surviving lineages.
Ivie said the research team knows its latest study has not solved every riddle that beetles pose, but it provides an evolutionary backdrop for future research on beetle diversity and their success.
To read the full paper, visit http://onlinelibrary.wiley.com/doi/10.1111/syen.12132/abstract.
Contact: Michael Ivie, (406) 994-4610 or email@example.com