has been argued that there is a core group of genes, especially those involved in DNA replication, which tend not to jump about, but remain in the same bacterial cell as it goes forth and multiplies. Whether this is true or not, it certainly seems that the majority of our genes do not find their closest relatives among the ‘true’ (eu-)bacteria such as the gut inhabitant E. coli, or the typhus-causing kin of the mitochondrion. Instead, the immediate ancestry of most of our body lies among another major group of prokaryotes, the Archaea.
