Give Now  »

Indiana Public Media | WFIU - NPR | WTIU - PBS

Noon Edition

How Butterflies Found A Place In The Sun

Read Transcript
Hide Transcript

Transcript

Y:        Good morning, Don!

D:        Morning, Yaël!

Y:        These winter mornings can be drab, Don; I look forward to birds and butterflies returning in spring.

D:        Yes, butterflies can always brighten a day. It seems fitting, being that they evolved from the drab moth when they moved into the daytime.

Y:        A great point—and over 200 million years ago. It wasn’t long after moths evolved special tubes for eating that a group of moths shifted to living during the daytime. The chance of finding more nectar from open flowers was a natural lure.

D:        For a long time, scientists thought that the moths that would eventually become butterflies were fleeing bats in the night. But Akito Kawahara and researchers at the University of Florida now say that the appeal of food probably shaped this evolution more than the threat of predators in the nighttime.

Y:        Although, bats and moths certainly had an evolutionary arms race: bats used echolocation to hunt moths, and moths responded by adapting the capacity to detect those sonic pulses.

D:        So, bats developed new frequencies that the moths couldn’t detect as well, but new moths were able to transmit sounds that threw off the bats’ measurements, or signaled that the moths were poisonous.

Y:        But regardless of how fiercely bats and moths have tried to outgun each other, that can’t have pushed butterflies to the daytime, since bats didn’t develop echolocation until 50 million years after butterflies showed up.

D:        It’s most likely that butterflies moved into the daytime to find more nectar from flowers that open during that time.

Y:        And eventually, butterflies shed their drab ancestral coloring and evolved coats of vibrant colors that advertise to mates and also send warnings to predators.

Monarch butterfly.

At some point, some moths started living during the day and evolved into butterflies. (Derek Ramsey, Wikimedia Commons)

Winter mornings can be drab, which is why many people look forward to birds and butterflies returning in spring. Butterflies are good at brightening the day. It sems fitting, since they evolved from the drab moth when they moved into the daytime over 200 million years ago.

It wasn't long after moths evolved special tubes for eating that a group of moths shifted to living during the daytime. The chance of finding more nectar from open flowers was a natural lure.

For a long time, scientists thought that the moths that would eventually become butterflies were fleeing bats in the night. But Akito Kawahara and researchers at the University of Florida now way that the appeal of food probably shaped this evolution more than the threat of predators in the nighttime.

Although, bats and moths responded by adapting the capacity to detect those sonic pulses. So, bats developed new frequencies that the moths couldn't detect as well, but new moths were able to transmit sounds that threw off the bats' measurements, or signaled that the moths were poisonous.

Regardless of how fiercely bats and moths have tried to outgun each other, that can't have pushed butterflies to the daytime, since bats didn't develop echolocation until 50 million years after butterflies showed up.

It's most likely that butterflies moved into the daytime to find more nectar from flowers that open during that time. Eventually, butterflies shed their drab ancestral coloring and evolved coats of vibrant colors that advertise to mates and also send warnings to predators.

Support For Indiana Public Media Comes From

About A Moment of Science