Fan dataminers delving into the source code of new Pokemon Go updates have discovered that a new attribute will be added to Pokemon in the game: gender. This may be the first step toward implementing a breeding system such as that used in older Pokemon games like Gold and Silver.
The dataminers also note that there is currently no code that would enable gender to be displayed to the player, so gender may simply be a hidden attribute for now while Niantic works on developing the breeding system.
Being able to breed Pokemon will add another dimension to the game for players, although it is not yet clear how it will function in Pokemon Go. It may simply prove to be an option for getting more Candy for a specific species.