👁️ Your Eyes May Have Evolved From an Ancient “Cyclops” Organ

Every vertebrate eye — including yours — may trace its origins to a single light-sensitive organ that sat in the middle of the head of a distant ancestor nearly 600 million years ago.

In a new Current Biology study, researchers from Lund University and the University of Sussex propose that an early worm-like ancestor lost its paired eyes after adopting a sedentary lifestyle. What remained was a simple median light-sensitive organ.

Millions of years later, as its descendants became active swimmers, evolution may have repurposed this central organ to form the paired retinas of vertebrates. The same ancestral system also appears to have given rise to the pineal gland, which today regulates our circadian rhythms and melatonin production.

If correct, this model could explain why vertebrate eyes are fundamentally different from those of insects and squid — and why the systems controlling vision and sleep may share a common evolutionary origin.

One important caveat: this is an evolutionary reconstruction, supported by anatomy, developmental biology, and neuroscience, rather than the discovery of a fossil “cyclops.”

📄 Paper: https://www.cell.com/current-biology/fulltext/S0960-9822(25)01676-8

#Evolution #Biology #Vision #Neuroscience #Science