Pelagibacter has just 1,354 genes, compared to humans, which have around 18,000 to 25,000 genes. It has none of the genetic clutter that most genomes have accumulated over time: there are no duplicate gene copies, no viral genes, and no junk DNA. The shorter length effectively means less 'work' to copy each generation as the bacteria reproduces. Also, base pairs are used that contain less nitrogen, since nitrogen is a relatively difficult nutrient for living things to obtain. The outcome, supported by their abundance, is a very efficient life form.