Working from beliefs -- Wizards, muggles and squibs

An exemplary study was just published in the issue of the British Journal of Medicine. The authors, led by Dr. Sreerarn V. Ramagopalan of Wellcome Trust Centre for Human Genetics at the University of Oxford, reviewed the literature for evidence on the genetic basis of magical abilities.

Yes, magic, as found in Harry Potter, the schoolboy wizard in the books by J.K. Rowling.

What? You don’t believe? Well, you may after you read the convincing arguments and hypotheses posed by the researchers.

Culling through the entire database on the cohort found in the seven-book collection, they examined the familial relationships between witches and wizards and their offspring: those with magical abilities, squibs without abilities and muggles squibs which have some magical ability.

The primary outcome measures were magical ability and specific magical skills.

“What is already known on this topic,” they said, was that magical abilities may be heritable. Only one example of the non-transmission of magic in a magical family resulting in a squib had been recorded, they noted. “Although shared environmental influences can also lead to familial clustering of a trait, the presence of magical abilities in seven generations of the Black family and at least three generations in others strongly suggests the influence of genetic factors in determining magical ability.”

Two pairs of monozygotic twins were identified in their study, and both had magical abilities. Despite the small sample size, they said, this finding lends credence to the idea of magic being genetically determined.

Harry Potter’s magical parents had died before his first birthday and he’d been raised by muggle relatives, the Dursley family, far removed from the magical world, much like an adoption study, enabling the researchers to disentangle genetic influences from those of the environment. But magical ability isn’t a dichotomous trait, the authors said. Abilities appear to have quantitative attributes likely affected by the environment, with experience and emotional state being important factors.

In this spectrum of magical abilities, they identified three skills that appeared to be conferred by specific genes:

One of these skills is speaking to snakes (parseltongue), known to be a feature of only direct descendants of Salazar Slytherin, one of the four founders of Hogwarts school. Another skill is clairvoyance. Sybill Trelawney, a professor of divination at Hogwarts school, is a seer and so was her great great grandmother. Lastly, Nymphadora Tonks, a character in the fifth Harry Potter book The Order of the Phoenix, was able to change her physical appearance (a metamorphmagus) and so was her son.

They also examined the possiblity of high rates of inbreeding and assortative mating, since most magical communities are isolated. This could result in a founder effect, with reduced genetic variation for the magical population. They hypothesized that this might explain why magical abilities appeared to be passed down to the next generation consistently when two parents with abilities bred. They were unable to determine the inheritability of the squib phenotype because no matings between squibs have been described. But magical ability appears to be a dominant gene, as matings between muggles and magical folks always resulted in offspring with magical abilities. However, the relative frequency of offspring with magical abilities when muggles mated argued against it being a simple dominant gene effect. “This could be explained, however, if muggles with magical abilities are those descended from squibs in previous generations who have integrated into muggle society.”

In the Discussion section, they interpreted their findings, saying:

The observed inheritance of magic in the Harry Potter books by J K Rowling would be best explained by a multilocus model with a dominant gene for magic, the function of which is controlled epistatically by one or more other loci, possibly recessive in nature. The genotypes of the loci concerned influence total magical ability, and the allele frequencies of these magical loci would differ significantly between populations with magical abilities and those without (muggles). We cannot yet confirm this finding, however, as those with magical backgrounds have not been included in the International HapMap project. Genetic heterogeneity may exist.

We hypothesise that a profound mutation in an evolutionary ancestor occurred in a histone gene, which radically altered genome wide chromatin structure. This created new sites of chromatin accessibility and altered gene regulation, including novel enhancer elements to drive “magical” type expression of genes (figure). Such magical enhancers would join a growing list of regulatory elements such as promoters, enhancers, silencers, insulators, and locus control regions. These regulatory elements are currently being identified and catalogued by the Encyclopedia of DNA Elements (ENCODE) Project Consortium, with analysis of 1% of the human genome recently reported. A dominant mutation in the histone gene could provide heritability of this epi-genetic effect. Such a mechanism originating in our ancestors would account for non-human magical creatures with some magical abilities (for example, house elves, goblins, centaurs). The basic human genetic structure still develops, making wizards and witches in most ways phenotypically similar to muggles. Squibs may result from an as yet unidentified compensatory epigenetic phenomenon, which returns the chromatin to near normal (muggle) function.

The rare ability to talk to snakes could be explained by mutations at the FOXP2 gene, and variants at the MC1R gene may explain the ability to change hair color. The highly polymorphic and various MC1R gene encodes the melanocortin-1 receptor, which is involved in regulation of pigmentation.

They conclude that all available information leads to certainty that some aspects of magical ability are heritable. However, without population studies to confirm the observed correlations, these findings should be treated with caution, they said.

This is an important study. While this was written in fun, it has some terrific and serious take-home messages.

Was this good science, do you think? The authors have impressive credentials, work for prestigious institutions, the study was published in a peer-reviewed journal, the scientific language sounded impressive, and it was highly referenced with 22 published studies.

Can we rely on these popular measures to indicate the soundness of a study’s conclusions?

Did the imposing science reel you in? Was the study data reliable? Did the study population represent you? Were the working hypotheses biologically plausible? Did the authors ever stop to question the core beliefs they worked from? And, most important, did they even ask the right question?

The ability to tell the difference between solid science we can use and junk science has never been more important, given the volume of tenuous science being published today. For an indepth look at “Distinguishing Science from Pseudoscience,” Dr. Barry Beyerstein, a professor of psychology at Simon Fraser University, has written an excellent explanation. [His paper is available as a free download here.] As he writes:

The prestige and influence of science in this century is so great that very few fields outside of religion and the arts wish to be seen as overtly unscientific. As a result, many endeavors that lack the essential characteristics of a science have begun to masquerade as one in order to enhance their economic, social and political status. While these pseudosciences are at pains to resemble genuine sciences on the surface, closer examination of the contents, methods and attitudes reveals them to be mere parodies. The roots of most pseudosciences are traceable to ancient magical beliefs, but their devotees typically play this down as they adopt the outward appearance of scientific rigor. Analysis of the perspectives and practices of these scientific poseurs is likely to expose a mystical worldview that has merely been restated in scientific-sounding jargon.

No matter how intuitively correct we believe “what is already known” on a topic or how popular it is, and no matter how strong or convincing the explanations for observed relationships might seem, it never hurts to question and take a critical look. :)