The EBV Infection Spectrum. EBV has a particular affinity for the cells that line the mouth and throat. Once the virus inserts itself into to a specialized immune lymphocyte (B cell), it hijacks the DNA to take control of the cell forever. When cells of the mouth and throat naturally slough off, EBV is shed into saliva.
Causing the Civil War. Historically, textbooks have taught that incompatibility between northern and southern economies caused the Civil War. The industrial revolution in the North, during the first few decades of the 19th century, brought about a machine age economy that relied on wage laborers, not slaves.
There were many factors that led up to the start of World War I in Europe. A lot of these factors were rooted in the deep history of the old powers of Europe including Russia, Germany, France, Italy, Austria, Hungary, and Britain. The real causes of World War I included politics, secret alliances, imperialism, and nationalistic pride. However, there was one single event, the assassination of Archduke Ferdinand of Austria, which started a chain of events leading to war.