"Here is why I think evolution is dangerous. The thought that nothing I do matters, it's all in vain, is dangerous for some people."
I agree that it is a dangerous belief in the minds of certain people. I know several atheists that are very dangerous people. One graduated in 2001, he has done a number of dangerous things. He has gotten high on acid (I do not remember exactly, it could have been something else), and jumped off of a very tall watch tower. He has a bad limp, and a cane, to this day. He is a smart person, a member of TAG, who has a full scholarship to the college he attends, and an IQ of about 165 (at least he did, when he graduated- it was taken two years after his jump). The reason he did it had something to do with the "Dungeons and Dragons" books. He told me that he thought that it would be "full as hell," and that it was "until [he] hit the ground." He said that he has no reason to regret it, and that it would not have mattered if he would have died, because he said he has "to die sometime, why not while I am having fun?" To the best of my knowledge, he has stopped talking about killing people, devising ways to rob banks, and such things. He did that to pass the time, but it started scaring people, so he stopped (they did not believe that he was joking, though I am not sure if I did). He loves messing with people's minds, especially exchange students' (I am not going into detail about what he does). He always stops before anybody gets seriously hurt, but I stopped helping him, for fear that someone would get hurt.
However, I also know dangerous Christians. Any belief can result in dangerous behavior, when taken to extremes (for example religious terrorists). People love to have stereotypes of people. They are just forms of schemas. I try not to judge people by other people's actions, or to judge people that do.
"If we are all just evolved monkeys, and when we die we just die, why should we even care what we do? Why should we hold ourselves up to a moral standard? Why don't we go into school and shoot our classmates?
Now, I'm not at all saying this is your thinking. But what do you think about right and wrong? If there is no God, and we are animals, then why is there a moral code at all? (Why do sane people think murder and rape are 'wrong'?)"
[I cannot answer one of these questions without answering all of them, so I will try to answer them all with one main idea.]
To survive, a culture must not try to kill itself. If the culture, as you can imagine, does kill itself, it will die. People need food, water shelter, etc. People want to be safe, to live a full and happy life. People do not want to be hurt, tortured, starved, killed, or anything else that is not comfortable. These rules apply to all people. An atheist that hurts or kills, just like a theist that hurts or kills, will not have a long and happy life here on earth (regardless of what happens after death). I am not ignorant, I may be wrong, I accept that. I do not claim to be right, I just simply have far more belief in evolution than creation. I have read most of the Bible (King James Version), and believe little of it. I do not believe that we lived with dinosaurs, that certain people lived several hundred years, that the earth is only about 10,000 years old, or many such ideas; they just seem too far-fetched, and unproven, for my belief.
For the most part, my moral beliefs probably coincide closely with yours. I believe that pointless killing is wrong (especially abortion, I have little respect for those who have had abortions, or have opted for the option of abortion). I follow the Golden Rule. I, to the best of my knowledge, live as a civilized, moral, respectful, and understanding person.