October 24, 2013
Bees Almost Went Extinct With The Dinosaurs
Brett Smith for redOrbit.com - Your Universe Online
According to numerous reports, honey bees around the world are facing a mysterious threat that has been wiping out entire colonies. However, this isn’t the first time bees have faced an existential threat. According to a new study in the journal PLOS ONE, the flying insects were almost wiped out along with the dinosaurs 65 million years ago.In the study, a team of Australian and American researchers modeled a mass extinction event for Xylocopinae, or carpenter bees, at the end of the Cretaceous and beginning of the Paleogene eras, commonly referred to as the K-T boundary.
Previous research has indicated widespread extinction among flowering plants at the K-T boundary and many paleontologists have assumed bees that relied upon those plants would have become extinct as well. However, a lack of fossil evidence makes the validation of such an event difficult.
"We were studying the relationship between bees in Africa, Asia and Australia. However, unlike dinosaurs that have left plentiful fossils, bees don't fossilize well, so their presence in the fossil record is very patchy," study author Mike Schwarz from Flinders University told ABC Science in Australia. "There are large numbers of bees found in 45 million year old amber, but not much before that."
The study team compensated for the lack of fossil evidence by using a genetic technique called molecular phylogenetics. By analyzing DNA of four "tribes" of 230 species of carpenter bees from every continent except Antarctica, the researchers were able to see clear evidence of a mass extinction. After evaluating limited fossil records, the researchers were able to introduce time into their calculations to determine how the bees are related and how old they are.
"The data told us something major was happening in four different groups of bees at the same time," said study author Sandra Rehan, an assistant professor of biological sciences at the University of New Hampshire. "And it happened to be the same time as the dinosaurs went extinct."
Rehan specializes in behavioral observation of bees living in the northeast region of North America. The new study utilizes the bioinformatics side of her research; cobbling together genomic data to clarify similarities and differences among the different species over time. By combining observations from the field with genetic data, Rehan said she can paint a more complete picture of bees' behaviors over time.
"If you could tell their whole story, maybe people would care more about protecting them," she said.
Rehan suggested that the new study could help to explain the ongoing loss in diversity of bees, an important species for agriculture and biodiversity.
"Understanding extinctions and the effects of declines in the past can help us understand the pollinator decline and the global crisis in pollinators today," Rehan said.
According to Schwartz, the study gives insight into the impacts of climate change because by looking at the past we can understand what might happen in the future. The connection between climate change and pollinator populations keep growing, he said.
"PhD student Scott Groom at Flinders has been looking at bee populations in Fiji and Samoa, and found that during the last ice age 20,000 years ago bee populations suffered,” Schwartz pointed out. "Any major climate perturbation has the potential to impact pollinators - and the plants they depend on."