Charles Darwin’s theories on evolution state that all life on earth developed gradually through natural selection over millions of years. By tracing two organism’s branching biological lineage backwards, at some point the two organisms would have been related to each other in one way or another. William McNeill contends that at a basic level that all living things behave alike and that humans are actually “macroparasites.” Well, we all know old habits are hard to change and there should be no doubt that humans and other organisms act like one another in order to continue their lives and species.
Disease is something that affects all of us, but what actually is disease? Many things cause disease. Some diseases can be contracted through drinking tainted water, others while having unprotected sex, and sometimes the mutations that occur during conception. Disease is basically anything that impacts an organism in a way that puts that organism at a disadvantage in a certain environment. Mental health problems and alcoholism are both things referred to as disease because both things put the person suffering at a disadvantage in their community. Diseases can be seen through various signs and symptoms that occur as a result of having the disease. For example, someone addicted to Facebook will show symptoms such as putting off worldly responsibilities or sleep to chat with friends on the internet. So, diseases can come in all shapes and forms.
Epidemics began to first manifest themselves around the time man-made the switch from hunting and gathering to livestock and agriculture. The close relationship shared between humans and animals allowed for bacteria and viruses to be passed from the animals to the humans. In most cases as the disease ends there but in other the disease adapts to the new human host and becomes a part of human life. Agriculture helped create larger groups of people living close together, which in turn helped diseases have a larger pool of hosts. These epidemics would usually kill a large portion of the population while leaving the ones behind who were genetically superior and resistant to the disease. By naturally selecting this group genetically superior group of people, the disease figuratively shoots itself in the foot and can’t walk over to a new host. Only time can heal this wound and once there is more non-resistant genetically inferior group of people around, the disease strikes again with the same ferocious intensity it did before. The Faeroes islands have shown how an epidemic could spread throughout a population and disappear by having all of infected people recover or die. Measles affected the islands in 1781 then it didn’t affect the island till 1846 when a Danish carpenter brought the disease back to the island.
In between these periodic waves of death, there is an opportunity for humans to reproduce and create more hosts. There is another scenario that can unfold. The community may create hosts...