Have you been watching the news at all recently? If so, you’ve probably heard the term “Swine Flu” bouncing around a lot. While most people come down with the normal human flu at some point, it’s not really a danger to anyone but the very young and the very old. Why is this flu different and what does it have to do with pigs?
The virus didn’t originate in humans, though. Birds, pigs, and even horses have their own versions of influenza. Remember the “bird flu” or “avian flu” scare a while ago? Scientists feared the influenza common in birds had “jumped the species barrier” and begun infecting humans. This is called a “zoonotic” disease - a disease that moves from animals to people. Now, the same worries have arisen about swine flu.
Avian and swine peplomers, on the other hand, are not easily recognized by the human system because our evolution did not include pressure from those particular viruses.
clipped from: www.geeksaresexy.net 