A Time Before Fire

Fire age.
Fire age.
Stephen Toner/Stone/Getty

Humans hardly invented fire, and yet if we travel back far enough in time, we encounter a time before the flame.

Remember, three ingredients are necessary for fire. As the boss is quick to remind us, you can't start a fire without a spark -- a heat source -- and that has been with us in the form of lightning strikes, volcanic activity, sparking rocks and meteorites throughout Earth's deep history.

Yet it wasn't till 540 million years ago, the beginning of the Paleozoic Era, that photosynthetic organisms terraformed the planet's atmosphere into an oxygenated balance capable of providing that necessary second ingredient: oxygen.

The third ingredient is fuel, and according to environmental ecologists Juli G Pausas and Jon E Keeley in "A Burning Story: The Role of Fire in the History of Life," it was indeed the last ingredient available, since terrestrial plant matter was scarce in this early age. The earliest evidence of charred vegetation dates back to a mere 440 million years ago.

And so fire came to define the New Earth -- geologic ages in which fluctuating oxygen levels contributed to the rise and fall of terrestrial burn rates. Make no mistake: cyclical wildfires shaped our world, playing an integral part in the evolution of flora and fauna.

When humans harnessed the power of fire, they began a long and destructive history. They ate. They expanded into new environments. They increased fire frequency and its destructiveness to ecosystems. Because while organisms don't adapt to tolerate fire itself, they do adapt to roll with particular regimes of fire -- surviving and sometimes thriving in the wake of naturally-occurring burns. Deviations from those regimes can prove devastating for the species that evolved to bounce back in the wake of forest and grassland burns.

About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.