Lizards Breathe Like Birds, One-Way Breathing Pattern May Be 270 Million Years Old getdiscountz.blogspot.com

getdiscountz.blogspot.com ® Lizards Breathe Like Birds, One-Way Breathing Pattern May Be 270 Million Years Old

A new study reveals that monitor lizards have a unidirectional way of taking in oxygen – where air flows through their lungs in a one-way loop. The findings, published in the journal Nature, reveals that the breathing pattern may be 270-million-years-old.

"That’s surprising that we don’t know something so incredibly basic about the biology of a group of animals," C.G. Farmer, the study’s senior author and an associate professor of biology at the University of Utah, told the Salt Lake Tribune.

Researchers found that monitor lizards throughout Africa, China, India and other parts of Southeast Asia, display this unidirectional breathing pattern. This differs from the way humans and other mammals breathe – where air enters the lungs through airways and then flows back out again the same way, known as “tidal” breathing. In birds, air enters the lungs in one direction, makes a loop before exiting.

“It appears to be much more common and ancient than anyone thought,” C.G. Farmer, the study’s senior author and an associate professor of biology at the University of Utah, said in a press release. “It has been thought to be important for enabling birds to support strenuous activity, such as flight. We now know it’s not unique to birds.”

Researchers came to the conclusion after studying lungs from living and dead monitor lizards. Using CT scans, 3-D images of lizard lungs to visualize the anatomy of the lungs and surgically implanting flow meters in the bronchi of five monitor lizards revealed the direction of their airflow. In 10 deceased lizards, researchers pumped water into their lungs filled with sunflower pollen particles to visualize the unidirectional air flow.

Birds were found to use this kind of breathing pattern in the 1930s.

"It was first noted in birds that were living in train stations in Europe," Farmer told LiveScience. "They were burning coal to power trains and noticed that only one part of the bird's lung was getting black with soot."

Scientists believe the one-way breathing is an evolutionary trait to help birds absorb higher amounts of oxygen, allowing them to fly at higher altitudes without getting tired or losing consciousness. Before the latest study, Farmer and others believed the one-way air flow started about 251 million years ago to help dinosaurs’ ancestors dominate the Earth when oxygen levels were low.

“But if it evolved in a common ancestor 20 million years earlier, this unidirectional flow would have evolved under very high oxygen levels,” she said. “And so were are left with a deeper mystery on the evolutionary origin of one-way airflow.”

The latest discovery might mean monitor lizards aren’t the only reptiles using this kind of breathing pattern.

"We need to look at other animals in different ecological niches, but I would not be surprised to find that this is very common in other cold-blooded vertebrates," Farmer said.

Lizards Breathe Like Birds, One-Way Breathing Pattern May Be 270 Million Years Old