How is it that staunch conservative Christian republicans believe in Social Dawrinism, but not evolution?

Christians believe in charity. Government entitlement programs have nothing to do with Christianity. It isn't that the majority of conservatives think the government should not provide any safety nets. The problem lies in the magnitude of them. 47 million people are on food stamps. That should be some indication to our government that there is something very wrong with their policies. Now you are likely to say that the economic policies are unrelated to your question but I believe they are at the heart of the problem. If the economy was better, unemployment would be far less and people would be earning better wages. That doesn't seem to be the direction we are headed.