Bees may have vanished from Earth along with the dinosaurs 65 million years ago - before the buzzing insects made a comeback - DNA analysis suggests.
For the first time ever, scientists have documented a widespread extinction of bees concurrent with the massive event that wiped out land dinosaurs and many flowering plants.
Lead author Sandra Rehan, an assistant professor of biological sciences at University of New Hampshire (UNH), and colleagues modelled a mass extinction in bee group Xylocopinae, or carpenter bees, at the end of the Cretaceous and beginning of the Paleogene eras, known as the K-T boundary.
Previous studies have suggested a widespread extinction among flowering plants at the K-T boundary, and it's long been assumed that the bees who depended upon those plants would have met the same fate.
Yet unlike the dinosaurs, "there is a relatively poor fossil record of bees," said Rehan, making the confirmation of such an extinction difficult.
Rehan and colleagues overcame the lack of fossil evidence for bees with a technique called molecular phylogenetics.
Analysing DNA sequences of four "tribes" of 230 species of carpenter bees from every continent except Antarctica for insight into evolutionary relationships, the researchers began to see patterns consistent with a mass extinction.
Combining fossil records with the DNA analysis, the researchers could introduce time into the equation, learning not only how the bees are related but also how old they are.
"The data told us something major was happening in four different groups of bees at the same time. And it happened to be the same time as the dinosaurs went extinct," said Rehan who carried the study with Michael Schwarz at Flinders University and Remko Leys at the South Australia Museum.
The study was published in the journal PLOS ONE.
