This is a too-common misconception. The Catholic Church teaches that the entire human race is descended from that one original couple: this dogma is called Monogenism.
Pope Pius XII addressed this in the 1950 encyclical Humani Generis. He said that it was “in no way apparent” how to reconcile polygenism (multiple original ancestors as in evolution) with divine revelation. Here is the full quote:
When, however, there is question of another conjectural opinion, namely polygenism, the children of the Church by no means enjoy such liberty. For the faithful cannot embrace that opinion which maintains that either after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all, or that Adam represents a certain number of first parents.Now it is in no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own.
The Catholic Church teaches the literal existence of a literal couple, Adm and Eve, as the first parents of the human race.
And by the way, 50+ years ago my entire Catholic Confirmation class was required to each own a copy of the whole Bible, all 73 books. Do you have that?
Yes, I DO HAVE many Catholic Bibles, both the older versions and the newest versions. I collect Bibles and rosaries. Not only do I have the Catholic 73 books Bibles, but have 3 Protestant Bibles, one NIV, one NKJV, and one large size Living Bible. Have one Orthodox Bible which has 81 books.
Haven't you heard? Doctrine has "developed." Just as with the historical truth of Genesis 1-11, "we now know" that Pius' views as expressed in HG were naive and pre-scientific.
Besides, whatever HG may say, the fact remains that 99.99999% of all Catholic/Orthodox bishops regard them as myths. An "official belief" that isn't actually believed is a poor argument.
Also, I notice that you don't argue for the total historicity of all of Genesis 1-11. So you then regard the Flood and Dispersal of Nations as a primitive myth, just as your bishops do with Adam and Eve? How do you know the "miracles" of the NT actually happened? Maybe they're hooey as well.
I do believe Pope Pius XII had been made an effort when he was Pope to get Catholics back into getting into reading the Bible once again. This was before VCII.
The 3 Protestant Bibles I do have in my collection have the 66 books.