These errors in the DNA only offer the traits , it is the enviroment that selects them, hence the term 'natural selection'. There is no intelligence involved at all.
Yes this is the key. There is no built in intelligence that decides to do anything. It's variation based on genetic mutations.
For example, i'll use a very silly analogy :). There are white people and black people, right? This is due to genetic mutations/changes.
Now let's say that there were giant predatory birds who went around eating humans, but somehow they can't see darker skin. What would happen? Well black people would thrive, and white people would have a hard time surviving and maybe go extinct.
Once white people were extinct what would happen to the big bad birds? They would likely go extict too. But what if there was a genetic mutation that made possible for a few of those birds to identify dark skin? Then that subset would thrive and the rest of the birds would die. And so it goes on.
Now, did something in the black human body decide to change color to avoid the big bad birds? No. The change was already there, but the enviroment was favorable to that change.
Over millions and millions of years this selection causes the collection of existing creatures living on the planet at any one time, to be contantly changing. This is what is called evolution.
I personally believe the very term "evolution" is creating an issue. People associate the term with a plan, a direction and they can't see a plan or a direction, without the existence of a planner or director. This is not the case. It's simply survival of creatures which are better adapted to living conditions vs extinction of the ones who are not.
