This is a clip of science writer Carl Zimmer's recent talk at The 2012 Singularity Summit about the roles viruses will play in the future of humanity. Deadly new epidemics, or virus built solar cells? Or both? Zimmer's book on this topic is A Planet of Viruses.
Since we are on the topic, back in June of 2012, Zimmer wrote that 8 percent of the human genome seems to derive from endogenous retroviruses (an article excerpted from his book A Planet of Viruses, mentioned above). Other research I have seen would make this a low number.
As Razib Kahn points out in Discover:
Additionally, this isn’t just limited to viruses. See: Horizontal gene transfer between bacteria and animals.
I think on of the chasms between geneticists and the public is that a lot of things that seem creepy and strange to the public are part & parcel of the geneticist’s professional toolkit. For example, to my knowledge no transgenic mice have turned into the Brain. I have friends that order weird mouse varieties, and then do weirder things to them, every week.