If it's part of natural selection, then why is it that no one has found any fossils that have more legs on one side or more eye sockets on one side, or something like that? Wouldn't there at least be fossils? Isn't it more likely that we'd find at least some fossils that were not very symmetrical than it is that all the symmetrical fossils that have been found were found.
An example of this is sticking a 'U' shaped magnet in a container of paper clips, nails, and safety pins, is it more likely that you will get the same number of each object on each side or that there will be a different number of each on each side.
Even though it IS possible that the first time you take the magnet out the sides will be symmetrical, how likely is it that every single step of evolution created a perfectly symmetrical creature the FIRST time? In the example of the magnet, how many times out of ten would you get the same number of each object on each side? Not many, so how many of the steps of evolution, where there are more possible outcomes, would end up perfectly symmetrical? Most likely not many.
In other words,
WHAT HAPPENED TO THE FOSSILS THAT AREN'T SYMMETRICAL?