"Retroviruses are fiendish things, even more devious and persistent than the average virus. They take their name from the capacity to move backward against the usual expectations of how a creature translates its genes into working proteins. Instead of using RNA as a template for translating into DNA into protein—the usual route by which genetic information becomes living reality—a retrovirus converts its RNA into DNA within a host cell; its viral DNA then penetrates the cell nucleus and gets itself integrated into the genome of the host cell, thereby guaranteeing replication of the virus whenever the host cell reproduces."

“If you can repair your future child's myopia with preemptive genetic tinkering, you might also want to increase her I.Q. by a few dozen points. Will it lead to a world as utopian as Lake Wobegon, where all the children are above average? Of course not. It will just add genetic manipulation of embryos and child cloning to the means by which affluent, fussy people try to distance themselves from bad luck, disappointment, menial work, death, and poor people.”

“People come into our lives and then they go out again. The entropy law, as applied to human relations. Sometimes in their passing, though, they register an unimagined and far-reaching influence, as I suspect Hughes Rudd did upon me. There is no scientific way to discern such effects, but memory believes before knowing remembers. And the past lives coiled within the present, beyond sight, beyond revocation, lifting us up or weighing us down, sealed away--almost completely--behind walls of pearl.”