How Mutation Causes Alzheimer's Disease
Your fate can be determined by tiny events. Imagine you live in the city and you walk everywhere to get exercise - you are healthy and not afraid of getting mugged. You almost never eat breakfast so you don't stop at the donut shop on the way to work, until one day the manager replaces the girl at the counter with her pretty red-haired younger sister. This seemingly unimportant change in your world is just enough to overcome your ability to resist high-fat temptation. A million donuts later, your cholesterol level surges and then your heart gives out. Curse you, little red-haired girl!
Like staff change at the donut shop, subtle, seemingly inconsequential differences in human genetic design can lead to some unexpected tipping points in cellular chemistry that can lead to disaster. Cellular processes, like all the routines of life, are unfathomably complex, constantly evolving, and are sometimes dramatically sensitive to the smallest of changes. Consider the case of Alzheimer's disease...