An international team of more than 100 researchers--including Dr. Michelle Trautwein of the California Academy of Sciences--has published the first modern roadmap of insect evolution. Understanding how insects are related uncovers their true ecological¹, economic, and medical importance, and, until now, has been largely unknown. The unprecedented² results, appearing in this week's issue of Science, reconstruct the insect "tree of life" and answer longstanding questions about the origins and evolution of the most species rich group of organisms on Earth. The results, published by scientists from the 1KITE project (1,000 Insect Transcriptome Evolution, http://www.1kite.org), are essential to understanding the millions of living insect species that shape our terrestrial living space and both support and threaten our natural resources.

 

"When you imagine a giant map of the evolution of life on Earth, insects are by far the largest part of the picture," says Trautwein, the Academy curator who contributed to the fly-related portion of the study. "We have not had a very clear picture of how insects evolved--from the origins of metamorphosis to which insects were first to fly. New sequencing technology allowed us to compare huge amounts of genetic³ data, and for the first time ever, we can fill these knowledge gaps. Science is taking us closer to solving the mysteries of the evolution of life than ever before."

 

Using a dataset consisting of 144 carefully chosen species, 1KITE scientists present reliable estimates on the dates of origin and relationships of all major insect groups based on the enormous molecular⁴ dataset they collected. They show that insects originated at the same time as the earliest terrestrial plants about 480 million years ago. Their analyses suggests that insects and plants shaped the earliest terrestrial ecosystems⁵ together, with insects developing wings to fly 400 million years ago, long before any other animal could do so, and at nearly the same time that land plants first grew substantially upwards⁶ to form forests.

 

"Phylogeny forms the foundation for telling us the who?, what?, when?, and why? of life," says Dr. Karl Kjer, Professor from Rutgers University. "Many previously⁷ intractable questions are now resolved, while many of the "revolutions" brought about by previous analyses of smaller molecular datasets have contained errors that are now being corrected."

 

The new reconstruction⁸ of the insect tree of life was only possible by a cooperation of more than 100 experts in molecular biology, insect morphology, paleontology, insect taxonomy, evolution, embryology bioinformatics and scientific computing⁹. The consortium was led by Karl Kjer from Rutgers University, USA, Xin Zhou from the China National GeneBank, BGI-Shenzhen, China, and Bernhard Misof from the Zoological Research Museum Alexander Koenig in Bonn, Germany.

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