Intraterrestrials: Discovering the Strangest Life on Earth

Lloyd, an environmental studies professor at the University of Southern California, debuts with an astonishing study of the remarkable microorganisms that thrive in the “subsurface biosphere,” which entails subterranean habitats “from the dirt right under our feet... to oceanic sediments piled tens of kilometers deep.” Recounting her daring research expeditions to study intraterrestrial microorganisms, Lloyd describes descending to the bottom of the Gulf of Mexico in a submersible too small to sit up in and hiking into the crater of the active Poás Volcano in Costa Rica to collect samples. She highlights the amazing strategies microbes developed to survive in such inhospitable environments, discussing how some organisms subsist on chemicals produced by the melting of rock, and how those in a highly acidic volcanic lake evolved “very small pore sizes on the proteins that span their membrane” to keep out protons that would otherwise pass into their cells and upend their internal pH levels. Other findings defy assumptions about the laws of nature. For instance, Lloyd notes that some microbes under the ocean floor survive on “0.00001 percent of the power that supports all other known types of cell growth on Earth,” suggesting they might spend millions of years in a state of suspended animation waiting to accrue enough energy to multiply. Filled with mind-blowing trivia that will change how readers think about life on Earth, this captivates. (May)