The Miracles of Predators and Prey

Long before the age of swords and shields, nature hosted its own evolutionary arms race.

Then, around 520 million years ago, a small marine creature fought a predator in duels that in part drove the Cambrian explosion, according to scientists. The period is known for its rapid diversification, explained Cosmos Magazine.

“Predator-prey interactions are often touted as a major driver of the Cambrian explosion, especially with regard to the rapid increase in diversity and abundance of biomineralizing organisms,” wrote study lead author Russell Bicknell of the American Museum of Natural History in the institution’s blog post.

For their paper, a research team analyzed hundreds of shells of Lapworthella fasciculata, a marine creature that is distantly related to modern brachiopods. The shells were collected from South Australia’s Flinders Ranges and ranged in size from a grain of sand to an apple seed.

Researchers were specifically looking for the interactions between the L. fasciculata and the mysterious predator known for punching holes in its armor.

Their findings showed that more than 200 shells bore these telltale circular punctures, likely made by a soft-bodied predator such as a mollusk or worm.

Using scanning electron microscopy, the team uncovered a fascinating pattern: The researchers could see that as more shells were attacked over time, the shell walls became thicker to resist the predators.

The thicker shells suggest that L. fasciculata rapidly adapted to resist predators. But its enigmatic foe was also evolving more effective techniques to pierce through the thicker shells.

The shells not only reveal the intense battles of early marine ecosystems but also highlights how predation fueled evolutionary innovation, the authors noted.

“This critically important evolutionary record demonstrates, for the first time, that predation played a pivotal role in the proliferation of early animal ecosystems,” Russell wrote.

The study also demonstrated how these evolutionary arms races have contributed to increasing specialization in predator-prey relationships. For example, snakes developed venom to kill its prey – but then its prey, such as rodents, developed resistance.