1 Unix The World’s First Computer Virus “Two of the most famous products of Berkeley are LSD and Unix. I don’t think that this is a coincidence.” —Anonymous Viruses compete by being as small and as adaptable as possible. They aren’t very complex: rather than carry around the baggage necessary for arcane tasks like respiration, metabolism, and locomotion, they only have enough DNA or RNA to get themselves replicated. For example, any par- ticular influenza strain is many times smaller than the cells it infects, yet it successfully mutates into a new strain about every other flu season. Occa- sionally, the virulence goes way up, and the resulting epidemic kills a few million people whose immune systems aren’t nimble enough to kill the invader before it kills them. Most of the time they are nothing more than a minor annoyance—unavoidable, yet ubiquitous. The features of a good virus are: • Small Size Viruses don’t do very much, so they don't need to be very big. Some folks debate whether viruses are living creatures or just pieces of destructive nucleoic acid and protein.