This question is one your hear pretty regularly from people of all ages from high school upwards. Rather than just thinking about the details of this question, you need to see it as part of the wider question of how science and Christianity relate.
Typically, that part of the scientific community which is hostile towards religion (Richard Dawkins who wrote The God Delusion is the captain of this team) is pitted against some Christians who are equally hostile in return. Dawkins argues that if you believe in evolution—the theory that more complex life forms evolved from less complex life forms through a process of natural selection—as a biological explanation then you must also believe it to be a philosophical explanation for everything. In other words you must also believe that everything has only a natural cause and that organic life is only the product of random forces guided by no-one. The Creation Science people say that Genesis 1 teaches that God created the world in 6 literal days a few thousand years ago, despite scientific evidence which suggests the earth is much older. With this combat approach a stalemate is reached.
There are a number of problems with insisting that the theory of evolution should move beyond a biological explanation of species towards a philosophical explanation of everything. Once evolution becomes the way of explaining everything we feel, believe, feel and do as the result of natural selection we have stepped too far, outside science and into philosophy (and have become unscientific in that sense). And not even atheist scientists agree that if you believe in evolutionary theory that you have to see it as the thing that explains everything in life.
We could just take a private approach to the question (which is the opposite of the combat approach) and say that faith is personal and subjective; it doesn’t say anything about evolution. God was the primary cause that began the world and after that natural causes took over (but what happens when God seems to interact with his world since then like raising Jesus from the dead?).
But in a more integrated approach Christians could say that Genesis 1 is more artistically crafted than Genesis 2, which has a more historic-scientific feel to it (although it sounds different to science as we know it today). This suggests that Genesis 1 is not supposed to be taken literally, in terms of 6 literal days, but that it is intended to show that God made the world in a good, ordered, and well-designed way, with humanity as the pinnacle of creation (being the only creature that bears the image of God). As far as evolution is concerned Christians could legitimately say:
- God created life and then guided natural selection to develop all complex life forms from simpler ones so that God is the cause of everything that is created without becoming overly involved in the process of evolution (this doesn’t mean he’s completely hands-off like in the private approach; the Bible tells us that God is even in control over the roll of the dice); or
- Some Christians consider the fossil evidence to be suspect or incomplete, some have noted that various species seem to appear rather than develop, and others have tuned into doubt within the scientific community that whole species can evolve from other species; these Christians would be happier to say that God performed large-scale creative acts at different points over a longer time frame (which could allow for the dinosaurs).
All this is to say that there is not “one true Christian position” on evolution—there are varying options for people who take the words of God in the Bible seriously as well as scientific discovery and thought. Certainly, we have said more than enough to say that the theory of evolution does not disprove Christianity.