Life as we know it wouldn’t be what is today without a lot of poop. In fact, Earth may have never hosted any life at all without experiencing a “fecal revolution” about 540 million years ago. “Next to rising oxygen levels and other contributing factors, the importance of feces in ancient ecosystems is often overlooked,” Russell Bicknell, an evolutionary ecologist at Australia’s Flinders University, said in a statement. Bicknell and fellow researchers laid out their argument in a recently published study in the journal Trends in Ecology Evolution. Their analysis focuses on ancient, fossilized fecal remnants called coprolites. This ancient excrement helps illustrate how and when animal life began to truly diversify on the planet. While the earliest and simplest organisms first arrived on Earth during the Ediacaran Period about 600 million years ago, it took another 60 million years for life to start growing much more complex. This era, known as the Cambrian Explosion, saw the very first intricate ecosystems populated by early examples of many major animal groups appear in oceans. We can see this exponential growth in complex life inside the preserved poop prehistoric animals left behind. After analyzing coprolite samples taken from over 35 sites around the world, researchers documented a clear shift in shape, size, and composition as the Ediacaran gave way to the Cambrian. These ranged from microscopic pellets to centimeter-scale fossilized feces containing animal fragments and shells. “With this shift, we see increasingly complex digestive systems, particularly in early anthropods which evolve[d] specialised foreguts and digestive glands capable of processing a wider variety of food,” explained Bicknell. The more these organisms ate, the more they excreted poop that was rich with nutrients and organic carbon. When these materials returned to the ecosystem, they helped foster even more life, which continued to diversify in a kind of evolutionary feces feedback loop. According to Bicknell and his study co-authors, the fossil record shows how evolving feeding systems coincided with more poop-derived organic materials needed for fostering an environment that could host all types of animals. It may not offer the prettiest picture, but it’s a cycle that has remained true for millions of years. As the team explained, the poop responsible for modern ocean conditions is not much different from the poop on land—and the fertilizer used to grow everyone’s food. The post Poop made life on Earth possible. Yes, poop. appeared first on Popular Science. ...read more read less