The Origin of Blinking Remains a Mystery to Science.
Blinking, a natural reflex of the body, is crucial for eye health and function. It serves many purposes, such as keeping the eyes clean, protecting them, and even conveying non-verbal signals. However, the origin of the blinking phenomenon remains a mystery.
To shed light on this topic, a team of scientists from the Georgia Institute of Technology, Seton Hill University, and Pennsylvania State University conducted research on mudskippers, aiming to understand why blinking is a fundamental behavior for life on land.
Mudskippers: The Strangest Fish on the Planet
Mudskippers are classified by the World Animal Organization as one of the 6 “strangest animals on the planet”, which includes: the walking catfish, the red wolf, the proboscis monkey, the Angora rabbit, the emperor tamarin, and the mudskipper.
The most unusual characteristic that sets mudskippers apart from any other fish is that they can live in saltwater, brackish water, and even on land.
They can even “climb” trees and skillfully jump from one branch to another, thanks to their pectoral fins functioning like hands.
Mudskippers are commonly found in estuarine areas, river deltas, and coastal regions in tropical areas, ranging from the Seychelles, India, and Bangladesh to Australia, including Southeast Asia (Indonesia, Malaysia, the Philippines, Thailand, and Vietnam).
A mudskipper on land. (Photo: Ecology).
In order to thrive in diverse conditions, mudskippers have adapted in a remarkably unique way. They can blink to keep their eyes from drying out, a trait rarely seen in creatures that primarily live underwater.
By comparing the anatomy and behavior of mudskippers with early four-legged animals, scientists observed a clear adaptation process for life on land in both groups.
“The results from this study raise a series of new questions about the diversity of blinking behavior we observe in various organisms,” said Tom Stewart, one of the study’s authors.
The Mystery of Blinking
Unlike most vertebrates, mudskippers do not have eyelids; they blink by moving their pupils down into the eye sockets.
However, this behavior does not require the evolution of many body parts in the fish, such as muscles or special glands. Instead, mudskippers utilize their existing eye muscles, but in a new way.
In a series of experiments, researchers discovered that mudskippers blink for three main functions: to moisten, clean, and protect their eyes. Interestingly, these functions also align with the reasons why humans and other terrestrial vertebrates blink.
According to the researchers, this single behavior in mudskippers helps them meet at least three complex functions and likely plays a crucial role in the historic evolutionary transitions of vertebrates, such as moving from water to land.
The origin of the blinking phenomenon remains a mystery. (Photo: Getty).
“We all blink every day without thinking. However, understanding why we blink is an intriguing puzzle right in front of us,” Stewart remarked.
“The phenomenon of blinking seems to reflect a larger question“, said Simon Sponberg, an Assistant Professor at the School of Physics and Biological Sciences. “What’s fascinating is how evolution can modify existing structures, allowing them to be used in new ways and for new behaviors.”
The research has been highly regarded by the scientific community for providing deeper insights into evolution.
