Evolutionary Leap

Oracle Text

G, Sacrifice a creature: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

Card Rulings

6/22/2015 No player will know the order of the cards put on the bottom of your library. Practically speaking, the cards should be shuffled (although this is not the game action of “shuffling”).
6/22/2015 If you don’t reveal a creature card, you’ll reveal all the cards from your library and then put them back in your library in a random order. (This is effectively the same as shuffling your library, although it’s still not technically a shuffle.)