Jacob lays Mother & MIB's bodies to rest at the caves, they are Adam & Eve

Jacob makes his way through the jungle to a stream and washes up. He looks up and sees the lifeless body of his brother on some rocks. Jacob weeps over the body, then picks it up and carries it to the cave.

Jacob lays MIB's body where they slept as children. He then goes to Mother's body and picks up the black and white stones and places them in a pouch. We cut away and see Jack and Kate discovering the pouch of rocks in season 1 with the "Adam and Eve" skeletons.

Jacob then closes Mother's eyes, picks her up and lays her next to MIB's body. We again cutaway to season 1 and Kate asks who the Adam and Eve skeletons are and where did they come from. Jacob then joins Mother and MIB's hands, kisses the pouch containing the stones and places it in MIB's other hand. We cut away again and see Locke calling the skeletons "Our very own Adam and Eve."

We then see Jacob looking over the bodies, still crying, and he says "Goodbye brother."

This was one of the biggest reveals of the series. While the clips from the season 1 episode "House of the Rising Sun" hit us over the head a bit with the significance of the Adam and Eve reveal, it did show us how far the story and these characters have come since Oceanic 815 crashed on the island.

With MIB's body being discovered by the creek indicates he is no longer human, but he still has the same goal of leaving the island. What would happen if this creature gets off the island?

Man (or boy) In Black finds Senet game on beach, convinces Jacob to play

As a young Man In Black walks along the beach, he discovers a game on the beach. The game is Senet is believed to be the oldest board game in the world, originating in ancient Egypt as far back as 3,100 B.C.

As he picks up the game, he looks out at the sea, or "Across the Sea." He goes and sits on a log and begins to set up the game with black and white stones. Young Jacob approaches him and asks what he has. MIB explains that it's a game that you play, and when Jacob asks how he knows how to play, MIB says "I just know."

MIB makes Jacob promise not to tell Mother about the game because he thinks she'll take it away. Jacob looks a the white piece and when MIB asks if he wants to play, Jacob says yes.

So this is certainly very similar to Locke's backgammon game in season 1. Senet is considered to be a precursor to backgammon. The game also gives us a general idea of when all of this is taking place. It would certainly seem to be sometime before the birth of Christ (B.C.), meaning that Jacob and MIB have been on the island for at least 2,000 years, if not quite a bit longer.

You'll also notice that one of the symbols on one of the squares is an ankh, the symbol we've seen a number of times, most notably this season when it was revealed that it was what was in the guitar case Hurley had been carrying.