Archive for April, 2009

Apr 30 2009

The Genetics of Autism

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A new genome-wide analysis of families with autism has found significant gene associations, adding to the growing evidence for strong genetic contribution to autism.  While this is still a long way away from explaining autism, it represents a significant advance in a very fruitful area of research.

But to put this into context, we need some background. Autism spectrum disorder (ASD) is not a single discrete pathophysiological disease. In fact, the term “disease” is probably not appropriate at all, which is why it is termed a “disorder.” Like many neurological conditions with primarily cognitive and behavior effects, ASD likely correlates with the organization and function of neurons in the brain – not a pathological disease process.

What this means is that there is likely to be a complex set of many factors that contribute to ASD – not one single cause. ASD is defined by the clinical symptoms that are evident – decreased social and verbal skills with a tendency to display repetitive behaviors or a narrow focus of interest. Brain function itself is highly complex, and these higher-order behaviors may just be the final common pathway of many potential underlying changes.

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Apr 29 2009

Anti-Vaxers In Australia

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The antivaccination movement is international, and our Australian skeptical brethren have been taking up the fight there (don’t be confused by the “c” in “sceptics.” I’ve tried to point this out to them, but they just won’t listen.) Dr. Rachael Dunlop of the Australian Skeptics, who does Dr. Rachie Reports for their podcast The Skeptic Zone, has written a summary of recent events.

The amazing part of this story, at least for somewhat jaded skeptics, is the mostly responsible manner in which Australia’s Channel 7 has dealt with this issue. It began with a report by Rebecca Maddern on “Sunday Night” which was an overtly scientific and pro-vaccie piece. Instead of token talking-head skeptics juxtaposed against amazing personal stories or kind-hearted (appearing) practitioners, there was token anti-vax cranks juxtaposed against children sick from vaccine-preventable diseases. Australia is apparently bizzaro-world for skeptics (maybe that explains the “c”).

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Apr 28 2009

GM Corn

Published by under Skepticism

Dr. Paul Christou and colleagues announced in the latest issue of PNAS that they have created a stable genetically modified (GM) version of South African white corn that has enhanced levels of three vitamins:

The transgenic kernels contained 169-fold the normal amount of β-carotene, 6-fold the normal amount of ascorbate, and double the normal amount of folate. Levels of engineered vitamins remained stable at least through to the T3 homozygous generation.

That’s precursors to vitamins A and C, and vitamin B9 respectively.  This is the first time a GM crop has been enhanced with more than one vitamin. The GM corn needs to go through the testing process, however, including animal testing for safety. It will likely be years before this corn is growing in the fields of sub-Saharan Africa – it’s intended target.

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Apr 27 2009

Anomaly Hunting

Published by under Skepticism

There are numerous ways in which thought processes go astray, leading us to false conclusions, even persistent delusions. Skepticism, as an intellectual endeavor, is the study of these mental pitfalls, for a thorough understanding of them is the best way to avoid them.

Science itself is a set of methods for avoiding or minimizing errors in observation, memory, and analysis. Our instincts cannot be trusted, so we need to keep them in check with objective outcome measures, systematic observation, and rigid control of variables. In fact bias has a way of creeping into any observation and exerting powerful if subtle effects, leading to the need to completely blind scientific experiments. Good scientists have learned not to trust even themselves.

One of the most common and insidious bits of cognitive self-deception is the process of anomaly hunting. A true anomaly is something that cannot be explained by our current model of nature – it doesn’t fit into existing theories. Anomalies are therefore very useful to scientific inquiry because they point to new knowledge, the potential to deepen or extend existing theories.

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Apr 24 2009

Pinniped Evolution

Published by under Evolution

The joke is getting so overused now it is becoming a cliche in skeptical circles – what happens when a paleontologist fills in a gap in the fossil record? They create two gaps, one on each side. But it is often used because it pithily exposes the intellectual buffoonery of those evolution deniers (aka creationists) who deny common descent. What is a “gap;” how big does it have to be to call into question common decent; or rather how small do the gaps have to shrink before creationists will accept common descent?

Perhaps the biggest outright lie in the creationist camp, still frequently parroted, is that there is a lack of transitional fossils in the fossil record. That is why it is important to showcase to the public the steady stream of beautiful transitional fossils that are being added to our already copious fossil record.

In the most recent issue of Nature, scientist present yet another pesky gap filled in with a transitional fossil, this one an early pinniped – which includes seals, sealions, and walruses.

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Apr 22 2009

A Personal Attack By J.B. Handley

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It seems I have gotten under the skin of notorious anti-vaccine crank J.B. Handley, the founder of Age of Autism. He recently wrote an entire article dedicated to the character assassination of yours truly. It seems I had the temerity to critique the latest anti-vaccination propaganda initiative called fourteen studies, an attempt to discredit the scientific evidence against a link between vaccines and autism.

Handley’s attack is an astounding example of hypocrisy, logical fallacies, and tortured reasoning. He really exposes the intellectual bankruptsy of the anti-vaccine movement, which is only reinforced by the supporting comments left by his avid readers.

He begins:

In general, I think the site (fourteen studies) so resolutely exposes the dirty underwear of the mainstream’s weak science on the vaccine-autism debate that most critiques of the site seem to center around the idea that “you have no need to go look at the site, and please pay no attention to the dirty underwear behind the curtain…”

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Apr 21 2009

Edgar Mitchell on UFOs Again

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Someone should tell CNN that Edgar Mitchell claiming the US government is concealing evidence for contact with extraterrestrial life is not news. I know it makes for eye-catching headlines, and of course that is the point, but really – Mitchell has been going around to UFO groups making the same claims for years.

The only thing that separates Mitchell from your average UFO believer is that he is a former astronaut.  This gives his claims a superficial air of authority, but when you actually examine his claims you find that they are not based upon his tenure as an astronaut. It is not as if he met aliens while he was in orbit. He has been a bit coy about how his time at NASA plays into his claims. He leaves open the suggestion that he was privy to inside information about UFOs in NASA, but has nothing concrete to give. (NASA, of course, denies any cover up.)

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Apr 20 2009

Occam’s Razor and Closed-Mindedness

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An SGU listener by the name of Jenny recently sent me the following question:

When we skeptics are faced with an unexplained occurrence, we work up a list of possible explanations based on our knowledge of how the world works and then use Occam’s Razor to prune out the most unlikely ones.

We often preemptively wield the razor by leaving off the list supernatural explanations that have been tried and debunked dozens of times. This is a tempting time-saving measure, but it’s also a violation of our proclaimed skeptic’s creed of being open to ANY explanation that is supported by evidence.
I often wonder how Richard Saunders manages to stick to the creed with such good humor–I don’t have the patience, myself.

This misuse of Occam’s Razor is, in a way, the reciprocal of the argument from ignorance–the argument from presumed knowledge, let’s say. For we skeptics to state categorically that a supernatural explanation CANNOT be true is just as much a logical fallacy as for a credulous person to state that our naturalistic explanations cannot explain the phenomenon in question. It also leaves us open to accusations of arrogance and closed-mindedness, which in this case actually have some basis.

This is a great question. While Jenny is a skeptic who is just trying to understand skeptical philosophy, similar arguments are often used by the proponents of various supernatural explanations, and so a detailed answer is helpful on multiple fronts.

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Apr 17 2009

Saving the Earth from an Asteroid

Published by under Skepticism

In Death From The Skies, Phil Plait discusses all the ways in which the universe might wipe out life on Earth. Perhaps the most obvious is by asteroid or comet impact. This one comes readily to mind probably because the current majority opinion is that the dinosaurs met their end at the hands of a large asteroid striking the earth near modern-day Mexico. This has also been the plot of two recent movies – Deep Impact and Armageddon, with nice visual effects of the impact.

Most readers are probably aware of the fact that the Earth is threatened by asteroids which cross our orbit. There are none right now on a known collision course with the Earth, but the threat remains. Apophis will come close in 2029 and 2036, but probably won’t hit. But eventually a large  asteroid’s path will intersect the Earth again – it’s just a matter of time.

Therefore astronomers have been thinking about ways to protect the earth from such an inevitability. One feature of any scheme to protect the Earth is the tracking of all near-earth objects. We cannot protect ourselves from a threat if we don’t know it exists. Also, the more lead time we have, the easier it will be to deflect an incoming rock.

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Apr 16 2009

Homeopathy for Cancer Treatment Side Effects

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The Cochrane Collaboration, an organization dedicated to evidence-based medicine, has published a review of studies of homeopathic treatments for side effects of radiation therapy and chemotherapy for cancer.  The results are unimpressive – consistent with the null-hypothesis that homeopathic remedies have no effect. And yet the review is being distorted to promote a very misleading bottom-line to the press – that homeopathic remedies have a role to play in cancer therapy.

One point has been made clear – the treatments under study are not for cancer itself, but for the side effects of standard cancer therapies: radiation and chemotherapy. However, the results are being presented as if they support the efficacy of homeopathic remedies, when they do not.

Homeopathy

Some quick background on homeopathy: This is a pre-scientific philosophy of medicine invented by Samuel Hahnemann around 1792. The principles of homeopathy are akin to sympathetic magical rituals. They include the notion that like cures like, or that a small amount of a substance that causes a symptom can be used to cure it. However, he then combined this principle with his “law of infinitessimals” which states that substances will become more potent as they are diluted, even if they are diluted beyond there point where any active ingredient remains. And finally he came up with the notion of succussion – that homeopathic remedies are given their power by shaking them 10 times in each spacial plane.

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