Draw three cards. You may play an additional land this turn.
3/14/2017 Urban Evolution’s effect allows you to play an additional land during your main phase. Doing so follows the normal timing rules for playing lands. In particular, you don’t get to play a land as Urban Evolution resolves; Urban Evolution fully resolves first and draws three cards, perhaps including a land you’ll play later.
3/14/2017 The effects of multiple Urban Evolutions in the same turn are cumulative. They’re also cumulative with other effects that let you play additional lands, such as the one from Explore.
3/14/2017 If you somehow manage to cast Urban Evolution when it’s not your turn, you’ll draw three cards when it resolves, but you won’t be able to play a land that turn.