Preston Estep et al. Dissent

The stated goal of the SENS Challenge was to demonstrate that “SENS is so wrong that it is unworthy of learned debate.” Whether or not this was accomplished by a given submission was to be determined by a panel of judges, and the final judges were self-selected from a large pool of people offered positions on the panel. Persons with relevant expertise were not included in the final panel of judges, leaving only those who know little or nothing of the existing learned debate within gerontology and life extension research. We have long objected to these and other aspects related to the judging of this challenge, and they have given us little confidence in its overall structure.

Therefore, we decided to direct all of our communications – including this response to the decision of the SENS challenge judges – primarily to the Technology Review readership. Since we don’t regard SENS to be legitimate science or engineering, we didn’t criticize it as a bad or immature example of either. We also didn’t attempt to show that SENS is demonstrably wrong, since this is extremely difficult to do with an untested plan comprising legitimate science bundled together with hand-waving speculations – even though the majority of these speculations cannot be taken seriously. Instead, we used this as an opportunity to describe general features of life extension pseudoscience and we used these general features to assess SENS. We showed that SENS is stereotypical pseudoscience, with its characteristic pervasive misrepresentations, diversionary sophistry, naïve and faulty science, and so on.

The summary of the judges’ opinion states that SENS is not “demonstrably wrong,” and Craig Venter says we have “not demonstrated that SENS is unworthy of discussion.” It seems they suggest that SENS is highly speculative theorizing but not outside the bounds of legitimate science or engineering speculation. We strongly disagree with this assessment. Here are three primary attributes of SENS that differentiate it from the kind of nascent science or engineering described by the judges:

1. Direct contradiction of key claims by much available and generally accepted evidence.

2. Aubrey de Grey’s pervasive falsehoods and misrepresentations.

3. Aubrey de Grey’s demonstrated misunderstanding of relevant science and engineering.

These attributes might not make SENS “unworthy of discussion” by willfully uninformed immortalist dreamers, but they certainly make SENS “unworthy of learned debate” by people interested in real gerontological science and engineering. The judges also write: “Some scientists react very negatively toward those who seek to claim the mantle of scientific authority for ideas that have not yet been proved. Estep et al. seem to have this philosophy.” We think a more appropriate statement of our philosophy is that we react very negatively toward those who seek to claim the mantle of scientific authority for ideas that are directly contradicted by a vast majority of current evidence, and are based fundamentally on misrepresentations of relevant science and engineering.

Curiously, the judges deemed our submission to be the best among three, but they disagree with our overall assessment that SENS is pseudoscience without even acknowledging the reasons why we reached our conclusion. They make no comment on any of our primary criticisms or on the presentation of evidence clearly demonstrating that SENS possesses the attributes listed above, attributes that strongly suggest that SENS is unworthy of learned debate. Why not? Is their silence an implicit acceptance of such attributes in early-stage science and engineering? If so, we strongly disagree. We think the presented evidence is clear and the judges have simply failed to further investigate the pattern of Aubrey de Grey’s misconduct, even though we presented to them ample justification to do so. Therefore, we provide even more evidence that Aubrey de Grey has made overtly and transparently false claims in his response to us, and despite the ease with which these falsities are found, the judges failed to detect or consider them.

Before we do this, however, we think it important to point out that all three submissions (and responses) to this challenge were very different but share two unifying themes: 1) Aubrey de Grey engages in deception and misrepresentation (we echo Charles Mobbs’ claim that “de Grey systematically misrepresents the scientific literature”); and 2) de Grey’s claim of SENS’ comprehensiveness is unjustified and unscientific. As we showed very clearly, these two are interrelated and many of de Grey’s deceptions and misrepresentations serve to bolster his claim of SENS’ comprehensiveness. Apparently, in spite of our many warnings that de Grey’s claims are often false, the judges did not investigate the truth of the claims in his response, even though he clearly directed his response to them.

We were reluctant to make a submission to this challenge for which a self-selected group of non-expert scientists act as arbiters of ideas outside their areas of expertise. However, we thought it important to take the opportunity to present to the Technology Review readership important information about SENS, in spite of the risk of ostensibly placing ultimate judgment in the hands of a panel of non-experts. We took this risk because we believe that certain key aspects of Aubrey de Grey’s claims and the judges’ assessment of them can be ultimately judged by the open-minded and technically competent readers of this magazine. Along with over two dozen of our scientific colleagues we recognize the extreme technical deficiencies of SENS[1] but we know that people outside of gerontological research don’t understand some of the arcane scientific minutiae. Therefore, from the beginning of this challenge we focused on conveying two primary messages to non-gerontologists: 1) there is no clear dividing line between legitimate science and pseudoscience, but there are general features of pseudoscience that can help us to identify life extension pseudoscience; and, 2) SENS is unworthy of learned debate because it has so few features of legitimate biological science or engineering and so many features of pseudoscience, including many false and misleading claims.

We believe that Technology Review readers can assess Aubrey de Grey’s claims and the judges’ decision by the same basic processes. First, they can read all the submissions and responses and they can see that all submitters accuse Aubrey de Grey of deception and/or misrepresentation. We did not discuss our submission with Mobbs or Weinstein, and such serious accusations are not made lightly or commonly in science; these accusations are no mere coincidence. Second, de Grey’s response to us contains so many false statements that we left a number of them unaddressed and we mentioned this in our response. These unaddressed falsehoods give a convenient measure of how thoroughly the judges assessed his claims. Once again, we don’t consider all previously unaddressed falsehoods since even a small number within scientific discourse should signal a serious problem, and if the judges allowed multiple falsehoods to go unchallenged then their final judgment must be discounted – or even totally disregarded. Some of the most easily discovered falsehoods are found in a passage in which Aubrey de Grey defends his claims regarding the absence of causal roles for mutation and epimutation in senescence. Here is the passage:

“…indeed, the data in the only publication[2] cited by Estep et al. that explored three or more time points suggests a deceleration (see figures 3 and 4 in that article). Thus, Estep et al.’s accusation that “a large body of scientific evidence on various pathologies and their possible contributions to aging is ignored” by me…is utterly baseless.”

This passage is particularly worth investigating because it seems authoritative and specific; it is the only specific citation or discussion of actual scientific data in de Grey’s response to us, directing attention to particular figures in a publication cited in our submission. The problem with this passage is that not a word of it is true, and in these two sentences there are three obvious falsehoods:

· Figures 3 and 4 of this paper[2] clearly show de Grey’s presentation of the data is false and one doesn’t need to be an expert to see this (although the meaning of these data will be lost on non-biologists). These figures show data on two types of mice: (i) normal mice, and (ii) mice bearing a translocation and mutant allele (with decreased function on the inactive X chromosome) at the assayed locus. The mutant mice show an age-dependent increased gene expression from the inactive X chromosome, with a plateau in expression at the two oldest ages (Figures 3C, and 4C). However, the normal mice, which represent the bulk of these data, show increasing gene expression from the inactive X chromosome at all ages and in both assayed tissues (Figures 3A and 3B, and 4A and 4B). These figures directly contradict de Grey’s claim of a deceleration of epimutation with advancing age.

· We did not cite only one publication with three or more time points. The Fraga et al. publication we cite[3] presents data from human twins of many ages, so, many chronological time points are represented in some of these data. It is true that the majority of these data are from twins in two age groups (one young and one older), but so what? This objection is misleading and it is an excuse to disregard the very strong evidence in this publication that compellingly challenges Aubrey de Grey’s claim of SENS’ comprehensiveness.

· Since Aubrey de Grey’s presentation of these and other data[4] are false and misleading, our accusation that he ignores a large body of scientific evidence stands unchallenged; however, this phrasing doesn’t sufficiently capture the essence of de Grey’s treatment of contrary data. While Aubrey de Grey does simply ignore most contrary data he does acknowledge some; however, he invariably misrepresents the meaning of these data to reduce the negative impact on SENS.

In the judges’ summary there is no mention of these or any other of Aubrey de Grey’s many misrepresentations. If the judges had listened to the SENS Challenge submitters’ unanimous chorus of accusations of deception and misrepresentation they would have discovered for themselves Aubrey de Grey’s obvious misconduct. Instead, our judgment is called into question, we are accused of name-calling, and the most severe criticism of this challenge is directed at us by Rodney Brooks. And what criticisms do they have of Aubrey de Grey? The judges determined that SENS is immature and speculative but Aubrey de Grey was spared any criticism. The absence of even an acknowledgment of his misconduct implicitly grants to him – and everyone else! – a license to distort and misrepresent scientific evidence to fit an agenda composed more of pseudoscientific propaganda than science or engineering. We believe that Technology Review readers are sophisticated enough to critically evaluate the judges’ assessment, to weigh the evidence for themselves, and to conclude that SENS is agenda-driven pseudoscience and unworthy of learned debate.

For a complete history of the SENS Challenge, click here.


1. Warner, H., et al., Science fact and the SENS agenda. EMBO Rep, 2005. 6(11): p. 1006-8.

2. Bennett-Baker, P.E., J. Wilkowski, and D.T. Burke, Age-associated activation of epigenetically repressed genes in the mouse. Genetics, 2003. 165(4): p. 2055-62.

3. Fraga, M.F., et al., Epigenetic differences arise during the lifetime of monozygotic twins. Proc Natl Acad Sci U S A, 2005. 102(30): p. 10604-9.

4. de Grey, A., Are nuclear mutations or epimutations relevant to other aspects of mammalian aging than cancer? Technology Review, 2006.

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