Ah! Very good question! How does 'faith' fit into idea of 'evolution'!?
I'm going to talk talk about what I described in the ''the evolution of religion" thread.
First of all: "What is faith"? Here's the definition http://www.dictinary.com gives:
1. Confident belief in the truth, value, or trustworthiness of a person, idea, or thing.
2. Belief that does not rest on logical proof or material evidence. See Synonyms at belief. See Synonyms at trust.
3. Loyalty to a person or thing; allegiance: keeping faith with one's supporters.
4. often Faith Christianity. The theological virtue defined as secure belief in God and a trusting acceptance of God's will.
5. The body of dogma of a religion: the Muslim faith.
6. A set of principles or beliefs.
The theory of evolution describes us as social animals. We have an inherent tendency to form and accept hierarchy. Hierarchy inherently brings forth the idea that 1 individual leads the group. (This can include female elephants leading a group of elephants, but it can also include a pride of lions being led by a dominant male.) Social animals have the tendency to FOLLOW the leader of the pride/group/pack/shoal/etc.
Following a leader IS a form of FAITH. The fact that we follow a leader is a direct consequence of our social capability of following an influencial person. BELIEVING that 1 individual can change our status/position is 'faith.' First we believe, and afterwards we expect the result of the promise... (in the case of religion)
We could say that faith is common to all social animals. Following any leader NEEDS faith to stimulate its followers, or else it wouldn't exist.
Wolves have faith in their leader, and a pride of lions has faith in their alpha-male. 'Faith' is inherent on social animals, and WE ARE social animals.