A reader writes:
I think you misread Farrell's piece. While giving Pius some credit for dealing with the issue of evolution, Farrell's main point was the caveat you mention second: modern biology shows man descends (as do virtually all species) from a population, not a single individual (or couple), and this contradicts Pius's assertion that the doctrine of original sin requires "a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own" (full text of Pius's Humani Generis here). Far from being prescient, Pius, as interpreted by Farrell, was thus wrong about what would be learned subsequently. Farrell is a bit off in not realizing that Pius was mostly concerned with addressing a 19th century idea (polygenism; not held by Darwin) that held that modern Homo sapiens has several independent origins (we didn't), and not with addressing modern evolutionary theory. I'm also not sure that Farrell's theologically correct: it's not self evident to me that common ancestry through populations violates the doctrine of original sin, although it might-- I'll leave that for Catholic theologians to decide.
I'm glad this elicited some feedback. [Only other gripe I came across was this predictable disagreement from a Baptist theologian.] Now, there are a couple of points to make. The first is, I am indeed aware that Pius did not define polygenism in the same way most biologists do now. He was quite right to reject the notion (which was popular in the 19th century) that the separate races had different origins. Still, his issue with the notion of a founding population of humans, rather than a single couple, is broached in the same paragraph of the encyclical, which makes it easier to confuse the two (also the Journal did not give me space to go into this detail).
The second is, I think Pius was wise enough not to be absolute about the issue. He wrote, "Now it is 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."
At the time he was, I think, on safe ground to say this. Science since then has raised this opinion to a fact, however. And this now requires invoking Galileo's approach to scripture, which he adopted from Augustine: when scripture is at odds with what can be factually determined, then scripture must be re-interpreted. So, I doubt any claim to making dogma out of Pius' statement on Adam will stand. [Even though some Catholics do treat it that way. See for example Mark's post and the comments here.]
Was the Pope mistaken about a founding population? Yes. Does it spell doom for original sin? Hardly. Even Chesterton dealt with this long before Pius. My own opinion is that what we've learned about human origins from evolution solidifies the doctrine more than any other religious notion. But there are entire books on the subject now.
What tends to get overlooked about Pope John Paul's thoughts on the subject are two things: one, that whatever separates humans from the rest of the animal kingdom is something only theology can be attuned to. What actually happened, the moment humanity made what he termed the ontological leap to something more than all the other species, is lost to history. But John Paul still urged theologians to think about this more.
UPDATE: 9.3.10: Some discussion now going on over at dotCommonweal.