Tuesday April 25, 2023
PennState —
An unusual blinking fish, the mudskipper, spends much of the day out of the water and is providing clues as to how and why blinking might have evolved during the transition to life on land in our own ancestors. New research shows that these amphibious fish have evolved a blinking behavior that serves many of the same purposes of our blinking. The results suggest that blinking may be among the suite of traits that evolved to allow the transition to life on land in tetrapods — the group of animals that includes mammals, birds, reptiles and amphibians — some 375 million years ago.
The study appears the week of April 24 in the Proceedings of the National Academy of Sciences and was led by Thomas Stewart, assistant professor of biology at Penn State, and Brett Aiello, assistant professor of biology at Seton Hill University.
“Animals blink for many reasons,” said Stewart. “It helps us keep our eyes wet and clean, it helps us protect our eyes from injury, and we even use blinking for communication. Studying how this behavior first evolved has been challenging because the anatomical changes that allow blinking are mostly in soft tissues, which don’t preserve well in the fossil record. The mudskipper, which evolved its blinking behavior independently, gives us the opportunity to test how and why blinking might have evolved in a living fish that regularly leaves the water to spend time on land.”