Author: Becca Dzombak
Edited by: Zuleirys Santana-Rodriguez, Emily Glass, and Whit Froehlich
In Lake Huron, off the coast of Michigan, lies a window to an ancient world. An underwater sinkhole holds water that’s chemically more similar to the ocean than to the rest of the Great Lakes. Microorganisms (microbes) thought to be very similar to those that thrived on Earth billions of years ago live at the bottom, moving around to chase the light and their preferred water chemistry. Geobiologists and biogeochemists are fascinated by this spot, called Middle Island Sinkhole, and the opportunity it presents to understand how ancient lakes may have supported oxygen-generating microbial communities, contributing to the rise of oxygen in our atmosphere. Using environments like Middle Island Sinkhole can help us understand the conditions in which life evolved on Earth (maybe even giving us hints for what to look for in our search for extraterrestrial life) and predict how carbon cycling in lakes might respond under climate change.