That's true if you were starting from scratch, with no tower. Obviously you'd have to come up with a plan for the foundation. Just as if you were trying to evolve life from a barren planet, you'd have to come up with a mechanism for the first life.
But that's not the situation we find ourselves in. Life is here, and evolution just describes it. Just as since the Eiffel Tower is already built, an engineer can figure out what keeps it up without reference to how the foundations were built. The foundation could be built in many different ways, and it wouldn't matter to a description of the iron superstructure.
The theory supposes everything came from little bugs, so WHENCE THE LITTLE BUGS, sir?
It doesn't matter. Evolution describes what happens after the little bugs are already here. I'm sorry, I can't say it any clearer than that, and your inability to comprehend it (if in fact you still don't get it) doesn't make it sophistry.
“It doesn’t matter.”
Yes sir, it does matter. A theory is required to answer such questions, otherwise it is a junk theory. WHERE DID THE BUGS COME FROM sir?