‘Often overlooked’: 540-million-year-old poop ‘revolution’ may be the source life as we know it New York Post How the 'fecal revolution' changed Earth's ecosystems Phys.org Poop made life on Earth possible. Yes, poop. Popular Science The Weirdest Theory Yet for Why Life on Earth Suddenly Exploded Gizmodo How animal feces became an evolutionary force 540 million years ago Yahoo