Bees are the most significant pollinators of flowering plants. This partnership began approximately 120 million years ago, but the uncertainty of how and when bees spread across the planet has greatly obscured investigations of this key mutualism. New research led by Universidade de São Paulo and Washington State University scientists demonstrates that bees originated in western Gondwana (Africa and South America) in the Early Cretaceous epoch and that the early evolution of any major bee lineage is associated with either the South American or African land masses.
“There’s been a longstanding puzzle about the spatial origin of bees,” said Washington State University’s Dr. Silas Bossert, co-senior author of the study.
For the study, Dr. Bossert, co-senior author Dr. Eduardo Almeida from the University of São Paulo, and their colleagues sequenced and compared genes from more than 200 bee species.
They compared them with traits from 185 different bee fossils, as well as extinct species, developing an evolutionary history and genealogical models for historical bee distribution.
In what may be the broadest genomic study of bees to date, they analyzed hundreds to thousands of genes at a time to make sure that the relationships they inferred were correct.
“This is the first time we have broad genome-scale data for all seven bee families,” said co-author Dr. Elizabeth Murray, also from Washington State University.
Previous research established that the first bees likely evolved from wasps, transitioning from predators to collectors of nectar and pollen
The current study shows they arose in arid regions of western Gondwana during the early Cretaceous period.
“For the first time, we have statistical evidence that bees originated on Gondwana,” Dr. Bossert said.
“We now know that bees are originally southern hemisphere insects.”
The researchers found evidence that as the new continents formed, bees moved north, diversifying and spreading in a…
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