Re: [asa] historical versus experimental sciences

Cameron,

It seems to me you make two claims in the below;

The first is that Hebert has no evidence for his speculations - but I think that's a wildly reckless assertion. Hebert is a professional biologist, after all, and I think one should assume that he speculates against a comprehensive background knowledge of the data. I would also suggest that he could readily cite evidence in support of evolution in particular, and neo-Darwinism in particular. And he certainly has evidence that there is a mitochondrial DNA bottleneck. Putting that all together, it's clear to me that his speculations arise precisely because of the existence of evidence rather than in the utter absence of same.

The second is that Herbert's speculations are interpreted within the context of a theory. But with apologies for a curt response, this is not a particularly breath-taking observation and I don't frankly know whether "so what?" or "tu quoque!" is the more fitting response. I do know that it causes me some bemusement that you consider such a practice somehow improper within the context of the sciences. What's more, to then critique Heberts speculations on the grounds that they are not testable - well, I can only say that a very large part of the art of scientific investigation is having the creativity to devise means to test speculative hypotheses. The strongest criticism one can legitimately make against Hebert's speculations is that there are AS YET no means to test them. The proper response to which situation is not to accuse Hebert of impropriety, but to go and devise some means of testing the hypothesis.

On top of that, I would make the following responses to a couple of your other remarks;

In regards to a purported "cavalier attitude" to the exact wording of people's statements - Herbert was responding to the questions of a journalist in an interview, for goodness sake, not formulating propositions for a journal article in analytic philosophy. Personally, I don't know Hebert, so I don't know how carefully he chooses his words. But I do suspect that you're investing Hebert's words with way too much significance.

In respects of the philosophical burden you place upon Hebert's concessions regarding "creationism" let me say that the failure to ask what is meant by the term in this context is no trivial matter - especially when you're accusing others of "a cavalier attitude to exact wording". You claim, essentially, that Herbert is trying to slam the door on the metaphorical divine foot, but how do you know that Hebert has anything such thing in mind? Perhaps by "creationism" he means "young earth creationism" and his reticence to be "honest" with the mitochondrial DNA evidence is precisely because, on face value, it implies something so obviously false that there MUST be an alternate explanation.

Now, that might be seen as an implausible judgement - but if anybody is entitled to make it, it's the professional biologist and I don't think s/he needs to prove the case to the layman's satisfaction. Actually, it's particularly ironic that at one and the same time Hebert is considered honest and competent enough to make the observation that "mitochondrial DNA bottlenecks are a problem for current formulations of neo-Darwinism" but is neither honest nor competent enough to assess this as an anomaly, nor to propose a mechanism by which such an anomaly might be explained.

If at the end of the day, all you are asking is for neo-Darwinists to be honest about the contrary evidence then my response is that you're being grossly unfair. Hebert DID acknowledge that the mitochondrial DNA is more consistent with a "creationist" paradigm than a neo-Darwinist one. And he is clearly of the view that neo-Darwinian theory as it stands does not fully take account of the evidence. So I don't precisely understand the tenor of your objection - I certainly don't understand your denigration of Hebert in particular or of neo-Darwinists in general. Nor do I understand why you would think Hebert's case actually evidences the position you seem to me to be advocating.

Blessings,
Murray

Cameron Wybrow wrote:
> Murray:
>
> In many cases, reformulation of a theory in the light of contrary
> evidence is both possible and the responsible thing to do. But when the
> reformulation involves postulating a currently unobservable and
> untestable entity or mechanism, an entity or mechanism which was no part
> of the original theory and is quite obviously being postulated only to
> rescue the theory, not because any independent considerations have led
> the investigator to think that such an entity or mechanism exists,
> eyebrows are rightly raised.
>
> Yes, Hebert is "allowed" to postulate a mechanism which explains the
> apparent conflict between the data and the expectations of Darwinian
> theory. But, as I showed with reference to the precise words of the
> conversation -- which I reproduced because I find that many people here
> have a cavalier attitude toward the exact words that people (including
> Darwin) use -- at the point of postulation, he acknowledged that he had
> no evidence, and only the motivation of rescuing the theory to guide
> him. His motive was in fact a compound one, to rescue the Darwinian
> theory and to make sure that "creationism" could not get a foot in the
> door.
>
> Does that make it impossible that such a mechanism exists? No. It
> might turn out that one does, and that his speculation will be
> vindicated. But let's be honest (as Hebert was honest in the interview)
> that (a) he was speculating in a fact-free way; (b) his speculation was
> generated by the desire to block a "creationist" inference from data
> which, by his own admission, supported that inference.
>
> Generally speaking, in science, fact-free speculations about entities
> and mechanisms which *might* exist are not encouraged; *some* empirical
> tether is expected of a proposal. I am no physicist, but I have read
> articles quoting physicists who have criticized string theory and
> multiverse theory on the grounds that they offer no prospect of
> empirical confirmation. And normally when it is obvious that the
> investigator is trying to hang to a theory at all costs, due to desires
> to sustain a certain broad view of the world, that is discouraged, too.
> When Lysenko hung on to a crude form Lamarckianism, in the face of
> contrary evidence, he was not admired by scientists for it, because all
> of them knew that his motivation was to sustain a view of biology
> favoured by the communist rulers of the Soviet Union at the time. It
> was thought that he was putting loyalty to a certain politics above
> loyalty to the cause of determining what was true about nature.
> Similarly, the *first* duty of a biologist who is investigating origins
> is *to find out what is true about nature*, not to make sure that he
> comes up with a theory that excludes "creationism".
>
> I am not saying, and have not said, that at the first sight of contrary
> evidence, scientists should abandon their theories. Nor have I said
> that neo-Darwinian theory should be abandoned because (if Hebert was
> right at the time of the interview) there was some powerful evidence
> against it in the mitochondrial DNA. All I have said is that Darwinians
> should be honest enough to say: "Yes, this evidence is more consistent
> with the expectations of design theory than with those of
> neo-Darwinism". But such words choke in the throat of neo-Darwinists.
> They can never admit that even *some* evidence favours the inference of
> design. Design has to be *all* wrong, and neo-Darwinism has to be *all*
> right. This "never admit a mistake, never admit any contrary evidence,
> never grant that your opponent has reason on his side" attitude of the
> neo-Darwinists is unscientific, unacademic, unphilosophical, irrational,
> and childish. That is why I found Hebert's statement refreshing.
> Despite his obvious prejudices, he frankly admitted that there was
> empirical evidence for design. You would never get such an admission
> out of the ideologues at the NCSE.
>
> In response to David Campbell and others, let me say that I am not
> endorsing all the claims that Dr. Hebert has made for the accuracy of
> genetic bar-coding in detecting new species and so on. I don't know
> enough about how it works and what the pitfalls of the technique are. I
> was interested only in demonstrating how external motivations clearly
> influence neo-Darwinian handling of the evidence, and taking my proof
> from the mouth of a neo-Darwinist as he talked freely with a science
> journalist. If the neo-Darwinists here cannot acknowledge that I have
> shown this external motivation, and if they cannot see why there is at
> least potentially a danger to good and honest science when external
> motivation leads to the *ad hoc* postulation of major complex mechanisms
> for which there is currently zero empirical evidence, then there is
> nothing more to be said regarding my example.
>
> Cameron.

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Received on Fri Aug 21 16:17:12 2009