Your DNA is what makes you you. But the robots and their scientists advocates have some other ideas. Recently some Caltech scientist have invented DNA nano-robots that can get in your blood stream and re-sort your molecules. This is a quote from the leads scientist:
"Just like electromechanical robots are sent off to faraway places, like Mars, we would like to send molecular robots to minuscule places where humans can't go, such as the bloodstream," says Qian. "Our goal was to design and build a molecular robot that could perform a sophisticated nanomechanical task: cargo sorting."
While its assured that these fine but naive young scientist are hoping for good outcomes, its not hard to start to imagine really bad uses for this technology. Qian goes on to say:
"it is my hope that other researchers could use these principles for exciting applications, such as using a DNA robot for synthesizing a therapeutic chemical from its constituent parts in an artificial molecular factory, delivering a drug only when a specific signal is given in bloodstreams or cells, or sorting molecular components in trash for recycling."
But someone in the pentagon (or a terrorist) could use this to create a zombie virus. You can easily imagine a nanobot that is self replicating and designed to reorder your molecules to make you a mindless tool. Breathe the nanobot in and within a few days you become a remote controlled mindless zombie. This scenario is not theoretical. If nanobots get built (and we can see that they are in fact getting built) then there will be military uses for them. Its just the way we are. We like killing each other.
The other disturbing thing about nanobots is the “The Grey Goo Scenario”. Almost all nanobot scenarios have a self replicating aspect to it. The problem with this is what if that ‘self replication’ gets out of control (naw – that could never happen), then we are totally screwed.
Eric Drexler describes the Grey Goo scenario like this:
Imagine such a replicator floating in a bottle of chemicals, making copies of itself...the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined — if the bottle of chemicals hadn't run dry long before.
Granted – this scenario is less about intentionally wanting to kill and more about blatant incompetence. The History Channel had a special where they outlined one scenario.
In a History Channel broadcast, a contrasting idea (a kind of gray goo) is referred to in a futuristic doomsday scenario: "In a common practice, billions of nanobots are released to clean up an oil spill off the coast of Louisiana. However, due to a programming error, the nanobots devour all carbon based objects, instead of just the hydrocarbons of the oil. The nanobots destroy everything, all the while, replicating themselves. Within days, the planet is turned to dust."
So maybe we intentionally wipe everyone out with Nanobots or maybe we accidentally do it. In some sense justice would be better served if stupidity killed us rather than malice. Its just the way we are. We are idiots.