Movie: I Am Legend...what is the significance of the butterfly?

Towards the end of the movie, he sees the butterfly tattoo on the woman's neck and you can hear the voice of his daughter telling him to "look at the butterfly". So I'm wondering, what does the butterfly mean? The first time the butterfly is mentioned is when he's in the car with his family, and his daughter keeps saying "Look at the butterfly". While he's picking corn, there is a butterfly too and if I'm not mistaken, he kind of stared at the butterfly. Last is the tattoo.

Could it mean that he's going to lose something? Soon after the first butterfly his wife and daughter dies. After the second one the dog dies. After the third one he dies.

Or is there no meaning at all to the butterflies?

It's a premonition. when he saw the pattern of wings that was smashed in the glass he remembered what his daughter said in his car years ago, and he noticed the butterfly tattoo. He then realized that God indeed sent this woman to bring the cure to the other survivors.

maybe it was a sign from god saying that anna was the one he was supposed to meet so she can carry on his legacy to that one place.

the butterfly is a sign......when the women said that she knows that there is a village because she listened to God. yea well its the same way with him he realises god was talking to him he just wasent listening . Why the butterfly? well because he always thought about that insect because that was one of the last words his daughter said.. PS God works in mysterious ways.