| Three enigmatic Archaea plucked from a pink scum, or biofilm, in California's Richmond Mine. Transmission electron micrograph (TEM) images like these show that most have protrusions (B), dark areas that probably are packed ribosomes (C) and unidentified dark inclusions (D). The 100 nanometer scale bar is approximately one-thousandth the width of a human hair. Credit: Brett Barker/UC Berkeley |
