In ‘pond scum,’ scientists find answers to one evolution’s which-came-first cases
…..Absent flowers, the researchers report, primitive moths and butterflies, known as the Glossata, developed the physical attributes – namely the sucking proboscis – to find nutrition by drawing off water droplets from the tips of immature gymnosperm seeds.
“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. They were feeding off the cone-borne seeds – mainly as a source of water,” said Strother.
Even Charles Darwin called the mysterious evolution of flowering plants “an abominable mystery.” Scientists have reckoned that flowering plants preceded the insects that fed off of them. But researchers have gradually started to piece together evidence that moths and butterflies existed earlier than the Cretaceous period, which began 145 million years ago.
The team’s findings shed new light on the classic example of co-evolution: the evolutionary interplay between pollenating insects – flies, bees, wasps, butterflies and moths – and angiosperms, or flowers, Strother said
“Our discovery does not change this, but instead, 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.”
Developing a clearer picture of insect evolution had proved elusive because much of what is learned from ancient rock, soil and fossils comes from earth once covered by oceans, said Strother. Moths and butterflies lived over land masses. In addition, their delicate features were prone to deterioration prior to fossilization.
