‘Profound ignorance’: Microbes, a missing piece in the biodiversity puzzle by Ian Morse on 26 April 2021 Researchers are certain that human activity has resulted in a decline in plant and animal species. But a huge unknown remains: what impacts have human actions —ranging from climate change, to ocean acidification, deforestation and land use change, nitrogen pollution, and more — had on the Earth’s microbes? A new paper poses this significant question, and offers a troubling answer: Science suffers from “profound ignorance” about the ways in which microbial biodiversity is being influenced by rapid environmental changes now happening on our planet. Researchers are supremely challenged by the microbial biodiversity question, finding it difficult to even define what a microbe species is, and uncertain how to effectively identify, analyze and track the behaviors of microbes on Earth —microorganisms estimated to be more numerous than stars in the known universe.