Using a molecular dataset consisting of 144 carefully chosen species of insects, researchers from the 1KITE (1,000 Insect Transcriptome Evolution) project have constructed the most comprehensive insect family tree to date.
This is the most comprehensive insect family tree to date; the time line at the bottom of the tree relates the geological origin of insect clades to major geological and biological events. Image credit: Bernhard Misof et al / Science, doi: 10.1126/science.1257570.
What the 1KITE team found is that insects originated at the same time as the earliest terrestrial plants about 480 million years ago, suggesting that insects and plants shaped the earliest terrestrial ecosystems together.
The scientists also determined that insects developed wings long before any other animal could do so, and at nearly the same time that land plants first grew substantially upwards to form forests.
“We dated the origin of insects to the Early Ordovician (about 479 million years ago), of insect flight to the Early Devonian (406 million years ago), of major extant lineages to the Mississippian (345 million years ago), and the major diversification of holometabolous insects to the Early Cretaceous,” the scientists wrote in a paper published in the journal Science.
“Insects are the most species rich organisms on Earth. They are of immense ecological, economic and medical importance and affect our daily lives, from pollinating our crops to vectoring diseases. We can only start to understand the enormous species richness and ecological importance of insects with a reliable reconstruction of how they are related,” said study first author Prof Bernhard Misof from the Research Museum Alexander Koenig – Leibniz Institute for Animal Biodiversity in Bonn, Germany.
“Insects are diverse, economically and ecologically important organisms. The biodiversity of insects is huge – they are the largest species group on the planet. While life on Earth began in the water, the first creatures on land and in the air were insects. Whatever people do, insects did it first. They waged war, they took slaves, they learned to work cooperatively, they flew, they farmed,” said study co-author Dr Jessica Ware of Rutgers University in Newark.
Prof Karl Kjer of Rutgers University in New Brunswick added: “many previously 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 scientists worked together to uncover relationships among insects as well as knowledge of their behaviors, flight, and more.
Although they developed transcriptomes (maps of the genomes) of 1,200 insect species, the current study only includes 144 species.
“We wanted to promote research on the little-studied genetic diversity of insects. For applied research, it will become possible to comparatively analyze metabolic pathways of different insects and use this information to more specifically target pest species or insects that affect our resources. The genomic data we studied give us a very detailed and precise view into the genetic constitution and evolution of the species studied,” said study senior author Dr Xin Zhouof BGI-Shenzhen in China.
The researchers have finished their analyses but due to the enormous size of the dataset, are still writing up their findings, with many more research papers to come.
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Bernhard Misof et al. 2014. Phylogenomics resolves the timing and pattern of insect evolution. Science, vol. 346, no. 6210, pp. 763-767; doi: 10.1126/science.1257570
