It is currently uncertain how much Plan B — the “morning-after” pill, which is a type of emergency contraception — works because of effects that take place after fertilization (i.e. a method ethically completely unacceptable to many, since it would be viewed as destroying a human), rather than (for example) by merely inhibiting ovulation, so that no fertilization takes place.

I pointed out a while back that the scientific papers in this area are being widely misreported. This, alas,  is still continuing. A recent article on Slate by William Saletan (following up on an earlier article) complained about the Vatican’s recent document Dignitatis Personae, where it said:

In order to promote wider use of interceptive methods, it is sometimes stated that the way in which they function is not sufficiently understood. It is true that there is not always complete knowledge of the way that different pharmaceuticals operate, but scientific studies indicate that the effect of inhibiting implantation is certainly present, even if this does not mean that such interceptives cause an abortion every time they are used. …

Saletan complains that “certainly present” is not correct. And if that wording were to be taken in the sense: “utterly beyond question” or “completely verified by a wide range of  studies”, then I would agree with him. However, if it is taken in a sense such as: “current studies point to this”, then I do not.

Saletan points to a 2006 JAMA commentary (i.e. significantly not a peer-reviewed scientific article) which tries to summarize then-current research. This commentary has the same problem as many such commentaries and abstracts: although internal details of the papers referred to are themselves very cautious — because the necessary data doesn’t exist, or only exists in a poorly statistical way — nevertheless the commenter makes it sound as though there are definite conclusions to be found.

For example, the commentary says:

Evidence that would support direct involvement of endometrial damage or luteal dysfunction in Plan B’s contraceptive mechanism is either weak or lacking altogether.

But evidence can be lacking because it has been looked for in many ways, and across many studies, and not found; or it can not exist because the necessary studies are extremely difficult to do, for scientific and ethical reasons, and hence there is simply not much possibility of gathering data. In the current case, it’s the latter. Simply saying “evidence is weak or lacking altogether” fails to represent which situation applies, and thus fundamentally misreports the science. One might just as accurately pick this quote out of the commentary:

women should continue to be informed, as they are now in the Plan B labeling, that its use may affect post-fertilization events

But somehow Saletan fails to pick that quote.

A subsequent 2007 study pointed to evidence that post-fertilization effects are present, and concluded:

Either the actual clinical effectiveness is far lower than has been estimated in the literature to date or mechanisms of action other than ovulation disruption must be contributing
to the clinical effectiveness. In our opinion, both explanations are likely to be contributing to the observed discrepancy between the level of effectiveness that can be attributed to preovulatory effects and the effectiveness reported in clinical trials.

(Alas, also misreported elsewhere.)

Nothing on this is decided, nor is likely to in the near future. Until it is more reasonably decided, beware the summaries and the abstracts.

No one will be able to cast serious doubt upon the scientific evidence for micro-evolutionary processes. R. Junker and S. Scherer, in their 'critical reader' on evolution, have this to say: 'Many examples of such developmental steps [micro-evolutionary processes] are known to us from natural processes of variation and development. The research done on them by evolutionary biologists produced significant knowledge of the adaptive capacity of living systems, which seems marvelous.' They tell us, accordingly, that one would therefore be quite justified in describing the research of early development as the reigning monarch among biological disciplines. … Within the teaching about evolution itself, the problem emerges at the point of transition from micro- to macro-evolution, on which point Szathmáry and Maynard Smith, both convinced supporters of an all-embracing theory of evolution, nonetheless declare that: 'There is no theoretical basis for believing that evolutionary lines become more complex with time; and there is also no empirical evidence that this happens.

Now the book by Junker and Scherer is a controversial German anti-evolution text; and the provided quote from the book by Szathmáry and Maynard Smith is one that has been horribly ripped out of its context, having nothing at all to do with any distinction between "micro-evolution" and "macro-evolution", and this has led one of its authors to complain that its use by Ratzinger was "misleading and inappropriate" (though it is probable that Ratzinger relied wholly — but wrongly — on Junker and Scherer for the appropriateness of the quote).

It is thus not unreasonable to suppose that Cardinal Ratzinger devoted little time to reading in science, and thus largely missed the scientific significances, contexts, errors and controversies of Junker and Scherer — in a way that he would be most unlikely to do for any philosophy or theology book.

Is that worrying?

On one hand, it's not worrying. Understanding science is not high on the list of expected duties of the vast majority of ordained priests, and so in general not much is provided to them.

On the other hand, more and more problems necessitate scientific understanding (evolution, cosmology, stem cells — and worse headaches to come) in order to locate them meaningfully within the realm of faith and morals. The difficulty (and it is an extremely widespread difficulty indeed) is that lacking a needed scientific understanding, people will often try to use only philosophy and theology in order to discuss these subjects — and that will often simply fail to provide useful answers. A bad scientific idea can be supported by appeals to good philosophy and theology. Then, lacking a good scientific understanding, some people may erroneously come to regard the bad science as good. (As has been seen in discussions of intelligent design, oh …. about a million times.)

(From other things, I know Ratzinger had a good idea of when he was starting to step inside the scientific field, and thus backed away a space.)

One of the most widely quoted scientific papers on this subject is Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation, by Croxatto et al. ( doi:10.1016/j.contraception.2004.05.007 ). The abstract of this paper includes the claim that levonorgestrel (LNG, the active ingredient in Plan B):

can disrupt the ovulatory process in 93% of cycles treated when the diameter of the dominant follicle is between 12 and 17 mm. It is highly probable that this mode of action fully accounts for the contraceptive efficacy as well as the failure rate of this method.

That is a very strong claim ("It is highly probable …" and "fully accounts").

So, isn't the claim of Ales Rarus thus confirmed? Well, we would have to look more closely at the body of the paper, not just the abstract. After all, at least one survey of the accuracy of the abstracts of articles in medical journals came to the startling conclusion that:

Significant results in abstracts should generally be disbelieved.

And this is important because the vast majority of people only ever read the abstract, and never examine the body of such a paper — as is well known to authors.

So, the first thing to look for inside the Croxatto paper is any indication of the numerical uncertainty of the results. Studies such as Croxatto's always have associated uncertainties, and it is extremely difficult to assess the reliability or probability of any conclusion without some indication of what those uncertainties are. In particular, we are looking for the basis on which the conclusion "highly probable" was reached.

There's nothing.

In fact, not only does the body of the paper not back up the claim made in the abstract, it only makes much weaker claims about the significance of the results. One conclusion in the body says:

Based on all the above, it is therefore plausible that the high proportion of cycles with anovulation or ovulatory dysfunction when the EC is given with follicles between 12 and 17 mm (93%), explains most if not all the contraceptive effectiveness of this EC method.

Somehow, without any given reasoning, what is merely "plausible" in the body, has become "highly probable" in the abstract.

Another part of the body of the paper says:

In conclusion, the results of this study indicate that when LNG is used for EC, it prevents pregnancy primarily by interference with the ovulatory process and that method failures are most likely due to treatment given too late to effect such interference.

Which is again a notably weaker claim than the one given in the abstract, since it only concludes (though again, without any provided numerical basis) that the study has identified a primary method of action, leaving entirely open what the scale of secondary effects might be. The abstract makes the claim that the effect "fully accounts" for things, but the body only claims that it is a primary effect.

So, Ales Rarus (and anyone else pointing to this paper) needs to dig deeper into the science of these issues before making claims, or relying on the claims of others.