[PatrickHenry]

Theory can only speculate how (a potential causal mechanism) a fact came to exist.

A theory (as science uses that term) does far more than that. Anyone can speculate. Every swami speculates. Every drunk in every bar speculates. Speculation is the cheapest coinage in the realm. Ah, but a theory ... it not only provides a cause-and-effect explanation of the observable, verifiable data, it also makes testable predictions.

[Lucky Dog]

[Theory]...also makes testable predictions.

Perhaps you could enlighten me on the testible predictions on experimental data of the the theory of evolution, particularly those not subject to valid refutation or explanation by an alternate mechanism.