Researchers from Washington State University have spearheaded a novel investigation that offers valuable insights into the origin and evolutionary journey of bees.
Their findings, documented in the scientific journal Current Biology, offer an in-depth exploration of bees’ evolutionary trajectory, their ancient roots, and how they have dispersed globally.
The study reveals that bees have been in existence for over 120 million years, tracing back to the primordial supercontinent, Gondwana, which would later separate into what we now know as Africa and South America. This latest evidence suggests that bees evolved and spread at a more rapid rate than was previously believed by many in the scientific community.
“There’s been a longstanding puzzle about the spatial origin of bees,” commented project co-lead Silas Bossert, an assistant professor in the Department of Entomology at WSU. He worked alongside co-lead Eduardo Almeida, associate professor at the University of São Paulo, Brazil.
With contributions from collaborators across the globe assisting in data collection and computational evaluations, Bossert and Almeida’s group scrutinized and compared genetic material from over 200 bee species.
They related these genetic analyses to traits identified in 185 bee fossils and extinct species, creating a comprehensive evolutionary timeline and hypothesizing the historical spread of bees.
Their research may be one of the most extensive genomic examinations of bees ever undertaken, with multiple genes analyzed simultaneously to ensure accuracy in their findings.
Elizabeth Murray, a co-author and WSU assistant professor of entomology, added, “This is the first time we have broad genome-scale data for all seven bee families.”
Prior studies suggested that the initial bees evolved from wasps, transitioning from hunters to gatherers of nectar and pollen. This investigation, however, positions the birthplace of bees in the arid territories of western Gondwana during the early Cretaceous period.
“For the first time, we have statistical evidence that bees originated on Gondwanaana,” Bossert claimed. “We now know that bees are originally southern hemisphere insects.”
The team discovered evidence that as continents drifted apart, bees migrated north, diversifying in conjunction with angiosperms, or flowering plants. Subsequently, they populated India and Australia. It appears all major bee families had diverged before the onset of the Tertiary period, approximately 65 million years ago—the period marking the end of the dinosaur era.
The authors highlighted that the lush flora of the western hemisphere’s tropical regions could be due to their long-standing association with bees. Around a quarter of all flowering plants belong to the diverse rose family, which serve as key host plants for bees in both tropical and temperate zones.
Moving forward, Bossert’s team aims to expand on their research, delving deeper into the genetic makeup and history of even more bee species. Their work is a significant starting point in understanding the co-evolution of bees and flowering plants. By grasping how bees have colonized and occupied their current ecological spaces, we may better protect vital pollinator populations.
Murray concluded, “People are paying more attention to the conservation of bees and are trying to keep these species alive where they are. This work opens the way for more studies on the historical and ecological stage.”
Image Credit: Andrew Murray