Do you think we evolved from other organisms?

You have an interesting argument that "Why didn't all of them(organisms) evolve" Well, I do have an answer to that question.In the process of evolution,very few,say one,organism mutates (genes altered,etc) and acquires slight change to its character and if that character proves beneficial,it can survive more easily.These favorably mutated organisms eventually lead to creation of a more successful new organism.Thus both types of species can exist,it's just that the evolved species is more advanced and better capable of surviving.Compare man and ape for the example.

But that still doesn't answer why all of them wouldn't change. Like if monkeys became men, there must have been some reason for it. Some need for it. Why didn't they all change? And how does a species change? Clearly they don't do it on their own. I've never seen one change into something else. I don't think any species would even imagine they had any ability to grow into something else.