The future of our World

In the year 2000 the worlds population was around 6 billion. In just 10 years our
population rose 1 billion. That means that from the beginning of time to the year 2000,
it took that many years to get a population of 6 billion, and in just 10 years we are at
7 billion. I believe that this rapid growth happed due to breakthrough in medicine. If
we continue to having breakthrough in the medical field life expectancy rates will rise
and eventually we will become over populated. What if some how in, some world wide
event, that mass amounts of people died out, and there was very few survivors left? It
would be up to them to re-populate the world. If it was only a few hundred that were
living in the same general area they would have spoke the same language. This world
would truly be a very different place. There would most likely be no crime. They would
have previous knowledge about how the world was ran, and being few amount of
people, they would be easy to control. How different would our world be if this were to
happen?