Ayala based his challenge to monogenism (two sole founders of humanity) on the large number of versions (alleles) of the particular gene HLA-DRB1, which are present in the current population.
What matters is that genuinely spiritual powers are either present or not, and that these alone bespeak the presence of true man.
The fact remains that a literal Adam and Eve are unchanging Catholic doctrine. Paul’s teaching is the fact that one man, Adam, committed original sin and that through the God-man, Jesus Christ, redemption was accomplished (Romans -21; 1 Cor. What they fail to notice, though, is that the Holy Father clearly insists that Scripture and the Magisterium affirm that original sin “proceeds from a sin truly committed by one Adam ” and that this sin is transmitted to all true human beings through generation (para. This proves that denial of a literal Adam (and his spouse, Eve) as the sole first genuinely human parents of all true human beings is not theologically tenable.
Second, rational human nature itself requires that mankind made an instant appearance on planet Earth.
Still, the technical concept of average effective population size estimates should not be confused with an actual “bottleneck” (a temporarily reduced population) which may be much smaller.
Effective population size estimates can vary from as high as 14,000 (Blum 2011) to as low as 2,000 (Tenesa 2007), depending on the methods used.