Originally Posted by nunayer beezwax

First of all I want to make clear that Evolution is not a "theory" in the colloquial sense of the term. Science today considers the "Theory" of evolution on equal footing with the "theory" of gravity. Suffice it to say that Evolution by means of natural selection is a Fact. That you are not convinced (yet) of its truth is (hopefully) a case of you not having been instructed properly in its teachings.

The terminology you use is not accurate to reflect what is actually taking place. You say that the "environment forces change". I'm not even exactly sure what this means, but it is definately not what evolutionists are saying. I don't know if you are familiar with the term "Natural Selection" but I believe that would be an appropriate place to start. Evolution of biological organisms is driven by the process of natural selection. Natural selection is something that happens to an individual, while evolution is a long-term process that occurs over many generations.

Complex organisms all have DNA, which can be viewed as a "recipe" for making the actual animal. Sometimes (rarely), when DNA is being copied (to form a new cell) there is an error in the copying process, this changes the recipe. So when the organism grows up, it is, in some physical way different from its parents. Sometimes these differences are helpful, in that they make this organism more likely to survive and pass on this new recipe to its children. This is a (very) simplified explaination but hopefully gives you the gist of what is going on. I will give you an example, though an exaggerated one:

Let us say that we have an animal that is identical with a Largemouth Bass in every respect except it does not have a tail fin. This means that mother and father bass both lack a tail fin, but out of their 4 children, one of them has a "mutation" in their DNA recipe which leads to it growing a tail fin while its three other siblings' DNA is copied correctly and they do not grow the tail fins. Since the addition of a tail fin is advantageous to a Largemouth Bass, it is more likely that the child bass who has the fin will have more offspring itself which also have the tail fin etc. and soon you have a race of Largemouth Bass whom all possess tail fins.

This process of "natural selection" is probably where you get the idea that the environment forces evolution. However evolution is not "forced" but rather a natural occurance by means of accidental copying errors in DNA which leads to physical characteristics which are (sometimes) helpful. Nature "selects" these creatures to have more children themselves and thus evolution takes place.

(This is obviously very simplified, but I'm trying to give you a brief overview of how this works, I would be thrilled to explain more and answer any questions this account brings to anyone's mind.)

Now, as to the question of why there are still monkies left since they were supposed to have "evolved" into humans. I'm trying to think of the best way to explain this please bear with me and ask for more if this doesn't answer your question.

All life, and by that I mean ALL life, has evolved from the very same beginnings. Human beings evolved out of bacteria just as they evolved from fish, amphibians, reptiles, monkies etc. Every species we see today on earth is on the same tree of life from root to tip. Now one of the beautiful consequences of life on this planet is that there are many "ecological niches", and nearly every one of them has some form of life that is adapted to it.

A tree is a very apt metaphor for the evolution of life. One species can branch off from another, and begin their own evolutionary path, while the original species can still continue on as it has, and each one fills a niche.

Again an oversimplified example. Apes, living in the savannah, near the edge of the forest, subsisting mostly on plants and the occasional large grazing animal have a baby who, due to a mutation in it's DNA, walks upright rather than on all fours. This baby is a much better hunter, for it can pick up things to throw at it's prey, it can see further, etc. So this new "human" is able to move from the treeline out further, expanding its territory and following the herds of animals that it kills for food until suddenly there is a whole tribe of these new "humans" living miles away from where the original "mutant" monkey baby was born.

Of course nothing about the new species infringes upon the tribe of monkies in the forest, and thus they continue on their merry branch of the tree, filling their niche, while the new species has moved on to fill theirs. This is the general principle of how there can be so many species on earth, the branching of the tree of life.

There is no magical ending place of evolution, and there is no prior intention. All evolution can do is operate on individual characteristics that make an organism more or less fit (survival of the fittest?) to survive and make more copies of itself. Though you may be tempted to think so, human beings are not "more evolved" than ground squirrels, we just fill different ecological niches. There are vast numbers of species that are very simple and yet are perfectly evolved to fill the niche in which they reside. Though a squirrel is "unexcpetable" to underwater living, other creatures are designed exactly for it and vice verse.