"By the strictest definition of species (absolutely unable to interbreed); speciation has been observed several times both in and out of the lab.
IF they interbred, then they weren't species by definition!
I'm sorry that I don't have the detailed answers in front of me which I think you might appreciate, to counter your claim. I might suggest a book by Michael Behe, or an easier starter, even Ann Coulter's Godless: the Church of Liberalism has a third of the book on evolution. You might try online Reason to Believe in Pasadena California as well.
What I do have: let's work backwards from something you might think is irrelevant but which is not. We have historical documents of eyewitness accounts of the life and resurrection of Jesus Christ in the Bible. The historical evidence is good,and the internal and external means to verify evidence are along the same standards as we would require in research of any other ancient document, verifying and affirming the claims.
Jesus rose from the dead proving His claims to be God the Son come to earth. Now, what does HE say about the beginning of the world? As God, He would know! He goes along with the teachings that the Bible is God's word and has accurate coverage of this. It is not a scientific textbook, but its account is true. The accounts in Genesis really happened, God actually created the beasts, and that man was created differently, "in the image of God." So we have God Himself, now who can be talked to, who has a fully human body because He has assumed a human nature along with His Divine nature, God the Son verifying that our historical records are correct for our cosmology.
We have a choice from there: when we hear theories which contradict Him, do we want to believe them, or Him? It is a widely accepted presupposition that miracles cannot happen, and yet Jesus raised Himself from the dead, so that 'scientific' presupposition is false, because the evidence overturns it. Do we want to believe a theory, or Him?
If evolution were true, God could have done it that way. But we don't have the evidence. What we have is lack of any evidence, with the godless liberals trying to push their anti-God beliefs upon us, not wanting this information to get out. There are changes within species, but there is no evidence that species evolve into higher species.
What you mean by "if they interbred, they were species by definition?"
And indeed there is evidence, a wealth of evidence indeed. To summarily assert that there is no evidence is intellectual dishonest.
Coulter's arguments were the same creationist arguments which have been continually refuted; also, Behe's IC proposition was shown to be false multiple times.
Evolution is not a belief, as you implicitly posit. It is however a scientific theory.