There’s a cyclopean ancestor hiding in your family tree...
Polyphemus, the towering, brutish son of Poseidon, is one of mythology's most enduring characters: a creature defined by the one eye in the middle of its head. With the recent arrival of Christopher Nolan's Odyssey on the big screen, cinemagoers have encountered a new take on the mythical tale. Now, researchers have discovered their own cyclops story – and this one isn’t fiction.
Scientists from Lund University and the University of Sussex have traced the origin of every vertebrate eye (including our own) back to a real single-eyed ancestor that lived roughly 600 million years ago.
Unlike Homer's monster this creature was tiny. It was a worm-like filter feeder that spent its life fixed in place, straining plankton from the sea with a single light-sensitive organ perched on top of its head.
As its descendants became active swimmers, that central eye was split apart and repurposed, with pieces migrating outward to form the two image-forming eyes that vertebrates rely on today.
And here's where it gets stranger. Not every part of that ancient eye disappeared.
The remnants of this ‘median eye’ survive in the human brain as the pineal gland, which no longer ‘sees’, but still governs the release of melatonin – the hormone that signals it is time to sleep as the light fades.
It may not be the hulking savage of Greek mythology, but the remnants of this creature remain, quietly dimming the lights each night from somewhere deep inside your skull.
(Image: TheAlphaWolf/Wikimedia Commons)