Is there any place where bacteria can't be found? Pick an environment, a temperature, an elevation, a climate, and a bacterial species calls it home. Scientists have found bacteria in every exotic habitat in the biosphere, says Thomas Whittam, a microbiologist at Michigan State University, East Lansing.
Why are they so ubiquitous? One ecosystem can't supply enough resources for the more than 109 bacterial species1 that exist, so they have adapted to different environments. Each species uses unique metabolic processes and defense strategies to survive, and thrive, in its niche.
How do bacteria survive? Their strength lies in their flexibility. Bacteria can adapt more quickly than larger organisms because of their small genomes and short generation times. Their "fluid genome" lets them "transfer entire pathways and get whole new functions," says Whittam. "There's nothing like it in higher organisms." Through horizontal gene transfer, some microbes share DNA that incurs greater ...
