Emma Morano, an Italian woman who is the oldest known living person in the world, recently celebrated her 117th birthday. Morano is the last known person born on the planet in the 1800s. She was born on November 29, 1899. The world population has grown by over 5 billion people during her lifetime. Here is a video about her.
The oldest known person who has ever lived was Jeanne Calment (image), a French woman who died in 1997 at the age of 122 years.
Sources: http://www.grg.org, USA Today, http://geography.about.com