This is Fascinating

http://en.wikipedia.org/wiki/Endogenous_retrovirus

If the information here is correct, then the entire evolution of mammals was spurred by an infection by the ancestor of the Human Immunodeficiency Virus (HIV), and thousands of inactivated copies of its genome persist. Infection with HIV might even cause production of these latent viruses. Its almost like HIV is a natural part of our evolution.

This leads me to the questions of :

• Is it possible that the creation of HIV was spurred by recombination between the Simian Immunodeficiency Virus and a related endogenous retroviral fragment ?

• Is the continued evolution of HIV accelerated by recombination with endogenous retroviral fragments ?