Regarding Reptiles


All photos by Jake Socha

 

The animal kingdom is constantly amazing us, offering scientists new information and insight to help solve questions we face on a day-to-day basis. Recently, two separate groups of GW researchers have been investigating unique characteristics of reptiles, and they’ve unearthed some incredible findings.

Snakes Take to the Skies

What’s that saying — snakes of a feather flock together? That can’t be right: Snakes don’t have plumage. But, as GW professor Lorena Barba and her team are aware, there are five species of snake that regularly take to the air, jumping from their perches atop the tropical forests of Southeast and South Asia and gliding gracefully through the skies.  

By leaping from treetops and flattening their bodies, snakes of the genus Chysopelea create aerodynamic drag, slowing their descent and allowing them to glide. They can cover up to 20 meters horizontally from a 10-meter high branch. One species, Chrysopelea paradisi, has even displayed the ability to turn in mid-air!  


By leaping from treetops and flattening their bodies, snakes of the genus Chysopelea create aerodynamic drag, slowing their descent and allowing them to glide.


Dr. Barba and her crew have been re-creating this phenomenon with a self-built computer model, using graphic processing units, as well as computational fluid dynamics and a Tesla K20 GPU accelerator. Dr. Barba next hopes to construct a 3D model to research how and why the snake moves in the air as it glides.

She said unraveling the mystery of the “flying” snake might offer solutions for real-world problems.

“It’s not wild to think that our understanding of the fluid mechanics of this particular shape could lead us to, for example, design a different type of air flow that is ideal for energy harvesting, or a wind turbine — or who knows,” Dr. Barba said. “You find applications in unexpected places.”

From Whence It Slithered

Reptiles are adaptable creatures when it comes to reproduction, according to new research by Alex Pyron, Robert F. Griggs Assistant Professor of Biology in the Columbian College of Arts and Sciences.

The ancestors of snakes and lizards likely gave birth to live young, rather than laid eggs, Dr. Pyron posits in a paper recently published in Ecology Letters, and it’s likely many species have switched back and forth in their preferred reproductive mode over time. The study also suggests that these frequent shifts in birth mode are a response to changes in ecological conditions.

“Before, researchers long assumed that the ancestor of snakes and lizards laid eggs, and that if a species switched to live birth, it never reverted back,” Dr. Pyron said. “We found this wasn’t the case.”

His research — supported by recent plesiosaur and mosasaur fossil discoveries as well as the fossil record of a few lizards from the Cretaceous period — pushes back the evolutionary timetable of live birth to 175 million years ago, much earlier than previously believed.

To draw this conclusion, Dr. Pyron analyzed the squamate evolutionary tree, in which lizards and snakes reside. The tree, which was created using DNA sequence analysis to group thousands of lizards and snakes, includes all families and subfamilies and most genus and species groups.

About 115 groups of lizards and snakes (2,000 species) have live birth. The other 8,000 species — at least for the time being — lay eggs.