Epidemic might end life on Earth. Throughout our history there have been epidemics that wiped out large percentages of the human population. There are lots of diseases that man doesn't have a cure for.The Black Plague, Influenza, and AIDS have all killed millions of people and there will always be new diseases that mutate into something worse, until at some point into something lethal enough to wipe out all of humanity. Old diseases such as cholera and measles have developed new resistance to antibiotics. Soon enough a disease with an extremely high death rate will develop resistance for all antibiotics and medicines. Now with international travel made possible for all humans diseases can spread faster than ever. The worst case scenario is a epidemic that spreads extremely qucikly, is unknown to us, and worst of all is lethal. Everyone could be caught off guard and before they know what is the source it might be too late.