50,000,000 is a year in which the professor, Bender and Fry went to via the professors Forwards Time Machine.
- Only Women (or a Human population of mostly Women) seem to exist with any males (young or old) being highly prized presumably for reasons of procreation. Also backwards time travel is invented. The high Female:Male ratio among humans is probably related to the gradual shrinking of the Y chromosome throughout evolution, eventually resulting in the lessening frequency of male humans born each generation.
- Also it must be noted that the women in this time are very attractive and wear very revealing clothes that show off their breasts and curves. Probably to make them seem more appealing to men.