Another good point about "theory" vs "law" in terms of science.
The reason why evolution is not a "law" is because we don't yet have the specifics enough to take numbers, and create a conclusion. To give a more visual explanation of what that means, we have the theory and the law of gravity:
The "LAW" of gravity simply gives the testable equation for how gravity works. It says "Every point mass attracts every single point mass by a force pointing along the line intersecting both points. The force is directly proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses"
This is a mathematical computation, that anyone with enough means can use to sufficiently come to a correct answer. You take the mass of two objects, and the distance, and you can figure out the gravitational compute.
The "THEORY" of gravity, is a explanation of WHY gravity behaves in the way it does. This theory is that objects of a higher density influence the attraction of other objects. There are visual respresentations based on this theory of space looking like a blanket:
http://s1088.photobucket.com/user/jarphys/media/framedrag.png.html
This description comes from the way we can actually use a blanket IRL and the tests are virtually identical to what the LAW of gravity predicts.
So, to summarise, the "THEORY" of gravity (which is most closely related to Einstein's theory of relativity, says that objects that are unevenly distributed among their environments create a spacetime bend.
Ok, sorry for all that, but it was important to explain exactly what LAW and THEORY means. Einsteins theory is fact. It just isn't a mathematical compute, its a description of WHY something happens. THEORY = WHY. LAW = HOW.
There is no "law of evolution" because we don't have a mathematical formula that allows us to look at a species and say, ok with this many genes, and this amount of radiation, and this amount of time, you can change this species to another.
However, that doesn't mean it doesn't happen. We see changes happen within species all the time, and on a bacterial level and viral level, we actually see species change to other species. That is because they are very simple organisms, which take much less time to visibly change. The more complex the creature, the longer it takes, but we've still seen changes in small insects. It is reasonable to conclude that we could eventually see a species change into another after several hundred years, given that we can see it happen in simpler life-forms.
