Thank you for the pithy clarification. I'm under the impression that Pius XII's formulation still stands:

<<Adam and Eve can be considered as figurative, but the event is primeval; meaning that there has to be a first couple.>>

This notion is untenable. We are to believe that no sooner had humans developed moral consciousness than they were brought to the test and failed, thereby condemning the human race to a fallen state in perpetuity until redeemed by the Christ and brought to fulfillment on the last day.

As you say, evolutionary biologists and anthropologists have discounted the probability of a "first couple." I have seen apologists jump through hoops to insist that yes, there was a first couple, in a desperate attempt to rescue what is clearly a myth about the origins of humanity and moral consciousness.  A bit of a problem for Christian theology.