The First Organisms to Blaze Trails

Half a billion years ago, a creature slithered across the seafloor for the first time. It may have launched an evolutionary arms race.

By Robert Moor
Oct 6, 2016 5:00 AMNov 12, 2019 5:54 AM
DSC-D1116_11.jpg
Paleontologists gather around fossil traces left by some of the first creatures to move themselves across Earth’s surface. | Ruth Schowalter

Newsletter

Sign up for our email newsletter for the latest science news
 

It is impossible to fully appreciate the value of a trail until you have been forced to walk through the wilderness without one. There is a practical reason why, for more than a thousand years, after the fall of Rome and before the rise of Romanticism, little was more abhorrent to the European mind than the prospect of a “pathless” or “tangled” wilderness. Pathless wildernesses still exist in the modern world, and at least some have retained their power to elicit dread. I have visited one such place. It lay on the northern rim of a glacial fjord called Western Brook Pond, on the island of Newfoundland, in Canada’s easternmost province. If you want to be taught (however harshly) the blessing of a well-marked trail, go there.

To cross the fjord’s stygian waters, I had to hire a ferryboat. On the far side of the fjord, the captain dropped me and four other hikers off at the base of a long ravine, where a series of animal trails led through a dense fern jungle and up a granite cliff face bisected by a waterfall. At the top of the ravine, I found a vast green tableland. The trail I had been following vanished altogether. Soaked in sweat from the hike up, I took a moment to rest, my feet dangling over the cliff’s edge. At the ragged western edge of the tableland, it abruptly dropped hundreds of feet to the fjord’s indigo water.

But this hike was a mere diversion, a side trip. My ultimate destination was a yet more baffling and inaccessible wilderness: the distant past. I was making my way to a rocky outcropping on the island’s southeast corner, where I hoped to find the oldest trails on Earth. These fossil trails, which are roughly 565 million years old, date back to the dimmest dawn of animal life. Now fossilized and faint, each one is roughly a centimeter wide, like a fingertip’s errant brush across the surface of a drying clay pot. I had read all about them, but I wanted to touch them, to trace their runnels like a blind man.

I hoped that encountering them up close would resolve a question I’ve long harbored: Why do we, as animals, uproot ourselves rather than maintaining the stately fixity of trees? Why do we venture into places where we were not born and do not belong? Why do we press forward into the unknown?

Cardinal Crawlers

0 free articles left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

0 free articlesSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

Stay Curious

Sign up for our weekly newsletter and unlock one more article for free.

 

View our Privacy Policy


Want more?
Keep reading for as low as $1.99!


Log In or Register

Already a subscriber?
Find my Subscription

More From Discover
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2025 LabX Media Group