In addition to any previous racial abilities and traits:
Gain darkvision 30 ft if they don’t have better.
Humans have been tainted by the demonic influence, and to a lesser degree the angelic response.
Humans may choose weather to have either an angelic ancestry or a demonic ancestry. Once that choice has been made they may either choose one variant ability from the aasimar or teifling table, or they may choose to roll twice on the relevant table. These choices take the place of skilled.