Animals have a lot to tell us, if we can figure out how to listen. Scientists around the world are racing to understand the myriad species that share our planet to aid conservation efforts and to help us see how they all fit together in the vast interlocking jigsaw that is Earth's ecosystem. Along the way, many of these studies are opening up our understanding of how humans fit into the evolutionary puzzle, and some discoveries are even leading to new technologies that may improve lives around the world.
This week, we pull from the archives an episode of Generation Anthropocene that explores the science of communication among elephants, songbirds and humans. Stanford student Lauren Gibson kicks things off with Caitlin O’Connell, a wildlife biologist who has been studying the complex social behaviors of African elephants. As part of her work, O’Connell and her team have been performing experiments to tease out the ways elephants talk to each other via seismic vibrations.
In addition to their familiar trumpeting calls, African elephants produce deep rumbles that actually set the earth moving. Other elephants can "hear" these calls using special cells on their trunks and feet called Pacinian corpuscles. "And those are vibration-sensitive cells that if you look at one under the microscope it looks like an onion. It has many, many layers. Those layers shift when there’s a vibration, and that sends a nerve impulse to the brain," says O’Connell.
This fieldwork does a lot more than help us eavesdrop on pachyderms—humans actually have Pacinian corpuscles too, and O'Connell's team has figured out an ingenious way to put them to good use. Hear more about their work with seismic communication here:
Next, producer Miles Traer chats with Stanford evolutionary biologist Nicole Creanza, who started out charting the evolution of birdsong. Birds are not born with distinctive melodies in their brains—just like humans, young birds must be taught the songs of their species, and interactions among individuals and across species have influenced the nature of birdsong over millions of years.
"I was looking at how changes accumulate in birdsong and whether you can use the songs of modern birds that exist today to think about the evolutionary history," says Creanza. But that got her thinking: can we also look at the changes of human languages through time to trace our own evolutionary history? And can that lead to even more refined insights than DNA evidence alone?
"We have this interesting parallel where you can inherit both genes and culture from your parents, but with culture you have the opportunity to learn it from other individuals as well. So my question, one of my motivations, was how much of the genetic patterns and the signatures that we see in human genes, how much of that is paralleled in language?"
Find out what Creanza has learned so far by listening to the full episode above.
Speaking of language and culture, this episode comes full circle with a return to O'Connell, who recently wrote a fiction novel called Ivory Ghosts. The book draws on her personal experiences in the field, using thrilling drama to highlight the very real issue of elephant poaching.
"I just feel like the truth sometimes is better told in fiction," she says. "It reaches a broader audience, an audience where I don’t feel like I’m preaching to the choir." Get the backstory on her fiction debut in the full episode.