Caves in the Bahamas, known as blue holes, have conditions similar to those on early Earth, giving scientists insight into how early forms of life on earth would have adapted and evolved in extreme conditions.
Scientists found that each of the three blue holes studied had specialised bacterial microbes. This suggests the microbial life in the pools is continually adapting to changes in light, water chemistry and food sources.
Some of the microbes live where layers of salt water and fresh water meet, and can chemically produce their food, meaning they can survive in extreme environments with little oxygen or light.
Read more at Texas A&M University