My father said as follows
Phages have always been described as bacterial parasites, but in the natural order of evolutionary progress it is not possible for the bacteria to arrive on the planet, (unless they were put there by a higher power), before Deoxyribonucleic acid (DNA), or DNA to arrive before Ribonucleic acid (RNA), or RNA to arrive before nucleic acids. Therefore the order of development should be, with perhaps a few steps in between:
Nucleic acids forming RNA
(single stranded) ssRNA Phage----------------ssRNA Phage
(double stranded) dsRNA Phage--------------dsRNA Phage
ssDNA Phage---------------------ssDNA Phage
dsDNA Phage--------------------ssDNA Phages
dsRNA Plasmids dsDNA
Bacterial cell
Sorry I missed a bit. He also says
The two life cycles of the bacteriophage
1. The lytic stage to synthesize new and more developed viruses leading to animal viruses
2.
2. The lysogenic stage for the evolution of bacteria and setting the basis of present day immunity and drug resistance in bacteria and viruses and animal cells.
This is point 2 above.