Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Monday, November 26, 2012

Bigfoot exists!... or, how science is not done

Well, the cryptozoological world has been buzzing the last few days about a press release from (in)famous Dr. Melba Ketchum, who has announced that her team has proven that DNA from a hair sample is from a non-human hominin species:
Our study has sequenced 20 whole mitochondrial genomes and utilized next generation sequencing to obtain 3 whole nuclear genomes from purported Sasquatch samples. The genome sequencing shows that Sasquatch mtDNA is identical to modern Homo sapiens, but Sasquatch nuDNA is a novel, unknown hominin related to Homo sapiens and other primate species. Our data indicate that the North American Sasquatch is a hybrid species, the result of males of an unknown hominin species crossing with female Homo sapiens.

Hominins are members of the taxonomic grouping Hominini, which includes all members of the genus Homo. Genetic testing has already ruled out Homo neanderthalis and the Denisova hominin as contributors to Sasquatch mtDNA or nuDNA. The male progenitor that contributed the unknown sequence to this hybrid is unique as its DNA is more distantly removed from humans than other recently discovered hominins like the Denisovan individual.

Sasquatch nuclear DNA is incredibly novel and not at all what we had expected. While it has human nuclear DNA within its genome, there are also distinctly non-human, non-archaic hominin, and non-ape sequences. We describe it as a mosaic of human and novel non-human sequence. Further study is needed and is ongoing to better characterize and understand Sasquatch nuclear DNA.
Well, that's just fine and dandy, but it's not really going to convince anyone who wasn't already convinced.  Because this, unfortunately, is not how good science is published.

This is, perhaps, the biggest misunderstanding about science on the part of the general public.  People have this sense that scientists go out and make discoveries, write them up, and the next thing you know, it's all over the "Science" section of Time magazine.  In fact, the first thing that should happen is peer review -- the data, methodology, and conclusions should be spread out for others in the field to take their best shots at.  Were the techniques used appropriate to the study?  Does the data unambiguously support the conclusion, or is there another conclusion (or more than one) that could be drawn?  Were reasonable controls in place to guard against bias, false positives, or sample contamination?

At that point, assuming that all went well with the peer review process, you trumpet your results to the public.  But not before.  In fact, that's been the problem all along with this study; hints and allegations were being made almost a year ago that the team had found something amazing, but the hard facts -- the actual data -- were shrouded in secrecy.  Months went by, and all we got were further teasers.  The whole thing was handled so as to maximize public hype -- rather like the whole kerfuffle over the "Baltic Sea Anomaly" (and notice how we haven't heard anything more about this non-story?).

Now, I'm not saying they haven't discovered anything; Melba Ketchum is a geneticist of excellent credentials, apparently, and it's hard to fathom why a reputable scientist would risk her career if there wasn't something real here.  (Although I am, reluctantly, reminded of the debacle over "cold fusion" that was handled in much the same way -- and the resultant irreparable damage done to the reputations of the two physicists responsible, Stanley Pons and Martin Fleischmann.)  What I am saying is that what has been released thus far isn't going to convince anyone who holds support of scientific discoveries to any usual standard of rigor.  So, predictably, the main ones who are greeting this press release with joyous shouts of acclamation are the ones who already believed Bigfoot was real before the study was even done.  Most of the rest of us are still sitting here, saying, "Okay, Dr. Ketchum, that's nice.  Now show us the goods."

This will, of course, earn more criticism for scientists and skeptics as being "closed-minded."  Actually, closed-minded is exactly what we're not; we haven't made our minds up at all, not until we've seen how the conclusions were reached, and whether the data support them.  It is to be hoped that Dr. Ketchum et al. will release more of their results into the peer-review system soon -- because until then, I'm afraid the response on the part of the rest of the scientific world will be lukewarm at best.

1 comment:

  1. The press release seems to be by way of Facebook. 'Cause scientists don't go through anything like PLOS Genetics or the International Journal of Zoology, ya know. Take it straight to the public, 'cause there ain't no need for scientific scrutiny.

    The sad thing is that cryptozoo's will forever more refer to this as 'proof' that the close minded scientists refuse to accept.

    Were the credulous fish, would be no need to bait the hooks.

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