That's not what happens. They continue to evolve into new things. They try out this gene and that gene and pretty soon they've gotten around the block. The world is getting smaller, tighter, more interconnected. People and products are on the move as never before.
Air travel means a disease can be half way around the world in a matter of hours.
There's no barrier you can put up against a virus. It can just move continuously across countries and across areas, says Dr. Michael Oldstone of the Scripps Research Institute. And the answer to that is yes. ABC News Internet Ventures. Click here for Terms of Use and Privacy Policy and Internet Safety Information applicable to this site.