Researchers found evidence of primitive butterfly and moth wings among ancient pond scum. Photo by Bass van de Schootbrugge/Utrecht University
Jan. 11 (UPI) -- Scientists have discovered evidence that moths and butterflies evolved 50 to 70 million years earlier than previously thought. The discovery suggests the emergence of moths and butterflies predates the first flowers, the opposite of what most scientists hypothesized.
"The consensus has been that insects followed flowers," Paul K. Strother, a professor at Boston College, said in a news release.
In 2012, while searching through ancient slides of leaf litter and sediment -- what he calls "pond scum" -- Strother found remains of primitive insect wings. The lace-like pattern reminded him of the wings deployed by the order of insects known as Lepidoptera, the group that includes moths and butterflies.
In the years since, Strother and his colleagues have amassed additional evidence that moths and butterflies emerged at least 200 million years ago. These early insects belonged to a suborder named Glossata.
In addition to wing fragments, Strother and his research partners found proboscises among the pond scum samples
"What we've found is that these butterflies and moths with mouth parts were feeding on pollen droplets of gymnosperm seeds -- from conifers related to pines, seed plants without fruits and flowers," Strother said. "They were feeding off the cone-borne seeds -- mainly as a source of water."
The discovery, published this week in the journal Science Advances, offers new insights into the evolutionary interplay between flowering plants and pollinators.
The emergence of flowers puzzled Darwin, but most scientists assumed flowers predated the earliest pollinators.
Strother's snooping upended the assumption.
"This is the old-fashioned science of discovery," said Strother. "We're looking at this microscopic world of things that lived hundreds of millions of years ago and we don't know what they are."
The latest findings don't negate the fact that the interplay between flowering plants and pollinators is a dynamic, back-and-forth affair. But it does provide new details about how the affair began.
"It demonstrates that the Glossata -- which gave rise to the Lepidoptera -- evolved earlier by a feeding adaptation to the gymnospermous ovules, or the pollen droplets," said Strother. "These insects later transferred their feeding preference onto angiosperms, and, as a result, ended up co-evolving with flowers where they function to transfer pollen as they feed on nectar."