Exponential Human Population Growth
Statisticians: Common Ancestor of All Humans Lived 5,000 Years Ago. That was the title of an important news article published in July of 2006 (here is a pdf version in case the link is ever taken down). The substance of the article threatens to throw icy cold water on more than just one Evolutionary doctrine. It showed that all of humanity is likely descended from a recent common ancestor who lived only 5,000 years ago, which fits very nicely with the timeframe of the Great Flood of Noah's day. Unfortunately, the monumental news story received little exposure, although Steve Olson talks about it briefly in his book Mapping Human History.
Exponential population growth was a major player in the computer simulation of the news story above. It is difficult for most people to fathom today's world population reaching it's current number in less than 5,000 years, but when the phenomenon of exponents is considered properly, it doesn't take any great leap.
As a kid, you may have heard the Exponential Allowance Riddle. It usually goes something like this:
"Jack and Jill's parents ask them how they would like to get their allowance.
The first choice is to get a penny on day one, two pennies on day two, four pennies on day three, and so on, doubling every day.
The second choice is to get a dollar on day one, two dollars on day two, three dollars on day three, and so on, adding a dollar each day.
Jill decides to get double each day starting with a penny and Jack decides to get an extra dollar each day.
After three weeks, who has more money?"
It only takes a few days before Jill's choice makes Jack look like a complete fool. Exponential growth in financial investments works very similar in human population growth. The main difference: it is generally measured in generations instead of years, but the growth curve looks identical and that is why more than 6 billion people can trace their ancestry back to a single common ancestor who lived less than 5,000 years ago.
His name was Noah and he lived about 4,400 years ago. A few hundred years after Noah, there lived a man named Ephraim, a grandson of Jacob. He was promised the "Fullness of the Nations" (Genesis 48:19) and we think he received the "fullness" of that promise. 
Also see: Exponential (Geometric) Growth.
