The simplest free-living organism is Mycoplasma genitalium, with a genome of 580,000 base pairs and 482 protein-coding genes. Carsonella ruddii has the smallest genome of 159,662 base pairs and 182 genes but cannot live on its own. Nanoarchaeum equitans was previously thought to be the simplest organism. Viruses are smaller and simpler than bacteria. Craig […]