I've heard this question asked about evolution a few times, I don't know the answer, and I've come to RDF for an answer to it.

When we talk about Everyone knows that evolution occurs by 1) a process of random mutations being passed on to the next generations, followed by 2) a sorting out of the inadequate from the adaquate by the process of natural selection. It is known that favorable muations are the ones that allow an organism to survive and reproduce. If an organism has a mutation that is hinders it survival and reproduction, it will leave the animal weaker and ultimately eliminate the bearers of that mutation from the gene pool. 

The question i need answered is what happens to mutations that neither hinder an animals' ability to survive and thrive, nor confer upon it any competitive advantage? Are they somehow deleted? Suppose over many generations my offspring developed a small claw underneath the upper arm. It would be useless. They couldn't use it for finding food, finding a mate, or fighting off predators. But the fact that it is not stopping them from doing any of those things means it should be passed on through the generations, right?

The question is why when we look at highly developed animals do we not see a bunch of useless things alongside the many necessary ones? Wouldn't you think it would be easier to randomly mutate a "neutral" attribute than one that might actually be good for something.

Example: Wouldn't one expect horned animals to have developed maybe a small horn growing out of the back of it's head pointing the wrong direction before it recieved two pointing forward that allow it to charge enemies successfully? Maybe they just chewed on grass unassertively and ran like hell when trouble came around while carrying around a stupid looking and ineffectual horn prior to recieving "combat" horns?

It's a thought that has made me think and all my thinking has yielded nothing so I am asking some people who may know.

P.S. It's hard to ask these questions in day to day life and tough to find time to do my own research so this internet tool is very cool.