The butterfly effect is a theoretical phenomenon stating that a butterfly flapping its wings in one place can cause catastrophic cyclones in other parts of the world. This theory is impossible to corroborate, of course, but it introduces an interesting question of what seemingly insignificant daily choices can have on the world; had John F. Kennedy's brother not volunteered for Operation Aphrodite, it is likely that JFK would not have ran for president. Imagine the impact this would have had on the world as we know it. Likewise, the decision of an Indian man to journey to South Africa caused immense world change; while moving country is an enormous decision, its worldwide ramifications are so pervasive that it is hard to find someone who has not heard of that Indian man: Mahatma Gandhi. The smallest decision can be the difference between any number of situations unfolding; to put the world, and your own existence, into perspective, it is worthwhile realising that - had just one of your ancestors been in the wrong place at the wrong time - you would not exist. Humanity is itself the product of an almost infinitely unfolding number of decisions, and there is an ample array of historical evidence to support this. Here we'll explore 10 of them.