Computer analysis of the genomes of extremophiles — organisms that live in extreme environments — reveals that their living conditions are recorded in their DNA.
Much like our gut microbes, the community of microbes used to process human waste must be healthy to do the job well. Monitoring the DNA in waste sludge can help us ensure the system stays healthy.
Fossil evidence of how the earliest life on Earth came to be is hard to come by. But scientists have come up with a few theories based on the microbes, viruses and prions existing today.