Apart from that, in just about any place compatible with carbon chemistry, life figures out how to be there. We violate probability, by our nature. Lewis Thomas Norman Pace, a microbiologist at the University of Colorado-Boulder, agrees. For the first 3 billion of the 3.8 billion years since life arose, microbes were Earth's only residents. In his office, Pace grabs a bottle of yellow muck taken from a salty pond near San Francisco.
Prokaryotes are smaller and simpler than eukaryotic cells.
They have no cell nucleus. The replication process goes about ten times as fast. Prokaryotes don't combine and specialize to form multicelled creatures. Prokaryotes are also called bacteria. The oldest rocks that could contain recognizable fossils contain evidence of domelike structures left by colonies of cyanobacteria and other bacteria.