Harry Potter Science # 4: The Botany of Wands

 Continuing the Harry Potter Science series (read parts one, two, and three if you missed them!), today we're looking at one of the aspects of wizarding life that is extremely important but also seems to be taken for granted: wands. Although it is possible to cast spells without using a wand, this is difficult and as a general rule a wizard/witch must have their wand on them at all times. This makes the disappearance of the legendary wand-crafter Ollivander especially disturbing, you can buy wands from other places but his shop is known to be the best. His disappearance only warranted a couple of mentions in Book 6, but I am predicting it will be highly significant in Book 7.

So, on to wands. Each wizard's wand is unique, and they vary in length, flexibility, wood type, and core. For example, Harry has an eleven inch wand made of holly, with a phoenix feather core. (This feather, incidentally, came from Dumbledore's very own phoenix, Fawkes, and the only other wand with one of Fawkes' feathers belongs to You Know Who...). Hermione has a dragon heartstring core, and Ron's wand has a unicorn hair core. (The phoenix, dragon, and unicorn cores are the only ones that Ollivander uses).

While the core of the wand seems to be highly significant, the wooden sheath has much to say about the wand owner as well. "The Trio," consisting of the protagonists Harry, Ron, and Hermione, all have wands made of the wood that the Celts assigned to the particular time of year of their birth (kind of like a tree-based zodiac). Harry's wand is holly, Hermione's is vine wood, and Ron's is ash. These are the only characters whose wands correspond to the Celtic tradition, but, as we shall see, the wand wood of all the characters is hardly arbitrary.

So we know Harry's wand is holly, what does that say about him, besides identifying an approximate date of birth? Although the berries can be slightly toxic, after they have frosted and thawed a few times they soften and provide food for many birds and insects. Also, holly bushes are known to be used by birds as refuges from predators. This seems to correspond to Harry very well. He is a very powerful wizard, and has traces of dark magic lurking in him despite his general heroics, such as his talents as a Parselmouth, something all wizards associate with the "toxic" dark arts. Just like holly berries, though, over the years his Parseltongue incidents have shown to be benign and he has regained the trust of those that were originally repelled when they learned about this hidden talent. As for providing refuge from predators, Harry is a star student in Defense Against the Dark Arts, and starts a club, Dumbledore's Army, in which he tutors other students on defensive techniques.

Moving on: everyone's favorite naturalist, Rubeus Hagrid. His wand is actually broken, and is concealed in a pink umbrella, but seems to serve him well nonetheless. It is oak, a tree also known as "King of the Forest," which seems fitting for Hogwart's grounds keeper and Care of Magical Creatures instructor. Oak also symbolizes strength and protection, which fits someone of Hagrids huge stature ("twice as tall as a normal man and five times as wide") and kind nature.

James Potter's wand was mahogany, a symbol of strength, which must have been true since he was known to be a powerful wizard and gave his life to save Harry. Also, there is a type of wood known as "stag mahogany", which is interesting because James was an animagus and his animal form was a stag. Interestingly, Lily Potter's wand was willow. It may not seem like a wand that symbols much robustness, but willow is commonly used in landscape management to prevent erosion, as a shelter/windbreak, and to help with biofiltration, all protective/caring functions fitting a good mother figure like Lily. Also notable, if not scientific: it has traditionally been thought to protect from evil, which is exactly what Lily did in the final act of her life: by dying for Harry, she somehow gave him a power over Voldemort that saved his life that fateful night and has served as his most potent weapon ever since. We still don't know the details of how this happened, hopefully it will be revealed in the last book.

And last, the one you've surely been wondering about: we know Voldemort's wand has the same core as Harry's, but what wood is it made out of? Yew. Yew trees are notable for two things that relate to Voldemort. The first is toxicity. The leaves, seeds, and fruit of this plant all contain poisonous alkaloids, which have been shown to cause potentially fatal heart problems in mammals. Nasty stuff that you don't want to play around with, much like everyone's favorite villian.

Druid cults often honor the yew: ("Dark tree, warder of time and ghosts buried long ago") for its extremely long life. There is a yew tree in Scotland that is thought to be 5,000 years old (picture credit to Barry Dunford). This is extremely significant, as Voldemort has been existing on the edge of death--but not quite gone--for sixteen years now, having partitioned his soul between horcruxes in his attempts to achieve immortality. The yew is also known as a tree of knowledge, and is often associated with fortresses--fitting to represent one of the most powerful wizards in the world.

So, there you have it, something as seemingly mundane as a species of tree can tell us much about a wizard/witch's character. Both the biological properties and legends about each type of wand wood seem to be highly significant, and it's worth the effort to pay attention to details of each character's wand, to see if JKR is dropping hints for us. I personally think that the issue of wands will be highly significant in the next book. We know that Ollivander has disappeared, and also that he had a wand displayed in his window that seemed to be highly prized by him, although we were never told why. We also know that Voldemort sought after relics from the founders of Hogwarts when gathering objects to use as horcruxes...could Ollivander be gone because he possessed the wand of Rowena Ravenclaw?

Also, we know that the last wand that Ollivander sold before he died was to Neville Longbottom, who is absolutely my favorite character. I have high hopes for Neville in the last book, and I think this detail about the wand is a clue that he is going to have a critical role in the final battles of the book.

By the way, Neville's wand was cherry, known for being strong and durable, (and also dense, a hat tip to his clumsiness and struggles in school). It was traditionally thought to protect from evil, and it contains anthocyanins (used to reduce pain and inflammation) and anti-oxidants, known to be beneficial for the immune system. I would say that this definitely supports my long-held view that Neville is definitely a guy you want on your team.

As a final parting note, just for fun: if all this wand talk has you hankering for one of your own, you can customize one here. The franchise opportunities never end!

Harry Potter Science # 1: The Genetics of Wizards

 In anticipation of the release of the Harry Potter and the Deathly Hallows (one week from tomorrow!), I'm going to do a series of posts linking the HP series and science in some way. I am a huge fan of the books (the movies are a waste of time, they are a disgrace to the books, READ THE BOOKS!), and even though they take place in a magical world, they can inspire a lot of interesting scientific questions to kick around for fun.

First up: the genetics of wizardry. What makes a person a wizard, and not a muggle? There was actually some discussion in the journal Nature on this very topic, back in 2005: a letter (Craig, J. Dow, R. and Aitken, M. Harry Potter and the Recessive Allele. Nature. Vol 436: 776.) and a rebuttal letter (Dodd, A., Hotta, C. and Gardner, M. Harry Potter and the Prisoner of Presumptions. Nature. Vol 437, p 318.).

The first letter claims that being being magical must depend upon a recessive allele. Wizards can have a variety of family histories: they can be born from a purely magical family, they can come from a strictly nonmagical family, or they can have one magical and one nonmagical parent (commonly scorned as "mudbloods" by haughty purebloods such as the Malfoys). Since wizards/witches can be born into muggle (nonmagical) families, Craig et al suggest that magical ability is a recessive trait (they designate the wizard allele as W and the muggle allele as M). They hypothesize that all wizards/witches are WW, which can result from a cross between two muggle "carriers" that are MW.

In the world of Harry Potter, pedigree is a point of pride in "pure blood" wizard families, and there are several times in the series when a character mentions that all of the remaining pure blooded families are linked by blood in some way, reminiscent of royal families that have limited their gene pools by avoiding out breeding. This implies that pure families such as the Malfoys and the Weaseleys are WW, since they have had no expression of dominant alleles in their recorded histories.

This isn't addressed in the letter, but it should be noted that in this system Harry must be a pureblood (WW), even though his mother came from a muggle family. Both of his parents were indeed magical, and if the gene is recessive then they must have both been homozygous for the trait.

It is not quite this simple, however, since sometimes magical families produce offspring that either lack magical abilities or have extremely restricted skills (these are referred to as "squibs", the Hogwarts hall Nazi, Filch, is an example). Also, Craig et al suggest that differences in levels of natural talent among wizards could be due to things like incomplete penetrance, or mutations, they give the hopelessly accident-prone Neville as an example.

The rebuttal letter, however, criticizes the view that magical ability can be chalked up to a monogenic trait. They argue that Neville cannot be a case of incomplete penetrance, because incomplete penetrance does not result in an intermediately expressed trait, it means that not all individuals inheriting the trait will express it, but those that do WILL express it fully. Dodd et al also point out that whether you claim incomplete penetrance or concede "variable expressivity", both of those phenomena are associated with dominant alleles, and couldn't apply to the recessive W. This letter concludes that it is not possible to determine that magical ability is unambiguously a heritable trait.

While Craig et al's original letter seemed intuitive, the Dodd et al letter makes some good points. Granted, you could chalk squibs up to mutations, and you could counter their problem with Hermione (how do we know she really has no family history of magic? It could be either intentionally or accidentally lost in family records, recessive alleles can hang around in the shadow for many generations). But their point about incomplete penetrance does strike a blow to the monogenic theory, and it does seem that something as complex and encompassing as magical ability would depend on more than a single locus.

So, the verdict, readers? If wizardry isn't a simple recessive allele, how, if at all, do you think it is inherited? Dodd et all claim there isn't enough evidence to show that magic is heritable, but how do you explain family trees like the Blacks, Malfoys, and Weaselys, with nothing but magic as far back as they go? There is obvious genetic isolation, with those families marrying only other magical families, but if the trait were not genetic then that shouldn't prevent muggles (or squibs, as they would be called in this case) from popping up at least occasionally...

This brings up another question, what could cause some magical families to produce squibs while some have no record of them? Where the Filches just unlucky, or are they genetically inferior to the Malfoys, as far as wizarding abilities go? Magical abilities develop with age, so by the time a squib became apparent it would be too late for infanticide. The poor nonmagical children could be sent off somewhere and not discussed again, but again, by the time a child is that age the community has usually noticed them and it would be difficult to explain their sudden disappearance. Plus, being a squib is undoubtedly embarassing, but the social stigma doesn't seem extreme enough to warrant exile: Filch has no redeeming physical OR personality traits to make him likeable, yet he still has a job at Hogwarts, one of the most important institutions in the wizarding world.

I have to close with one thing statement that needs to be made, although it doesn't directly relate to genetics: I don't agree with them using Neville as an example of partial/poor wizarding ability. He is by far my favorite character, and I think too many people underestimate him (I also HATE the casting for him in the movies, bah). Yes, he is awkward, forgetful, unlucky, and accident-prone. But he has shown courage in many critical moments, and it is known that the prophecy about Voldemort and Harry's fates could have equally applied to Neville, Voldemort unwittingly chose his enemy and it was just chance that it turned out to be Harry facing the Avada Kevdavra that night instead.

Also, Neville has developed a strong talent for herbology. He is not a dunce, he just took a while to find his niche, it seems. My biggest prediction for book 7 is that Neville will have a key role as a hero, I've been saying that since the 2nd or 3rd book. He got noticeably short shrift in the last book (6, Half-Blood Prince), but I think he will come back strong in the finale.

Ok, that's all for now, look for more Harry Potter science in the days to come!

Brightly Colored Birds More Affected By Chernobyl

On ScienceDaily today, a really fascinating report on how the Chernobyl meltdown has affected some bird species more than others. They studied 57 species, and found that those that have had the most drastic declines since the disaster fall into four groups:

1. Species that depend upon dietary carotenoids for their red, yellow, or orange plumage (orioles, blackbirds, blue tits, for example).

2. Species with relatively large eggs.

3. Species that migrate.

4. Species with wide dispersal patterns.

Apparently all of those groups have lifestyles that place a high demand on antioxidants (for plumage coloration, flight energetics, etc). The study suggests that high levels of radiation have a disproportionately negative impact on species that require lots of antioxidant compounds. Radiation levels in a normal (ie not post-meltdown) environment vary due to natural things like differences in isotopes between different geological features, and the researchers suggest that these new discoveries can be used to make predictions about species success in places where radiation levels can be quantified.

It is important to realize, from the data in their report, that some of the species studied fall into more than one of the high-risk groups: for example, orioles depend on carotenoids for their yellow plumage (see image above), and also migrate long distances.

Also, another thing I gathered from the report that I thought warranted a note: bird species that are taxonomically close might not be impacted to the same degree as less-related species with similar lifestyles (meaning, you can't necessarily predict the impact on a species by looking at stats on a sister species). For example, in the family Paridae, blue tits, which are highly dependent on carotenoids, have faced much sharper declines than coal tits.

I've always been fascinated with the Chernobyl meltdown (it's one of the landmark events in the year I was born, btw) and its impacts on the local wildlife. Despite my unabashed mammal and dino bias as far as interests go, the radiation-eating fungus recently discovered there is still definitely my favorite science story of 2007 (see my blog post on it here). One thing that is both interesting and sad is that some reports have shown that wildlife has actually benefited, in some ways, from the catastrophe, since human activities in the area have effectively ceased.

Quotes of the day

"How is it that hardly any major religion has looked at science and concluded, 'this is better than we thought!' The Universe is much bigger than our prophets said, grander, more subtle, more elegant'? Instead they say, 'No, no, no! My god is a little god, and I want him to stay that way.' A religion, old or new, that stressed the magnificence of the Universe as revealed by modern science might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths."

Carl Sagan in The Pale Blue Dot

"The distinguished embryologist Lewis Wolpert once admitted that science is occasionally arrogant, and he went on to remark, mildly, that science has a certain amount to be arrogant about."

Richard Dawkins in Unweaving the Rainbow

Worm-like jellyfish

There is a really fascinating article on Science Daily today about Buddenbrockia, a small organism previously that has long been thought to be a nematode worm, but now known to be most closely related to anemones and jellyfish. It has no gut, mouth, brain, or nerve cord, and although it was long thought to be a type of nematode, it has a very different body plan (the main distinction: Buddenbrockia is symmetrical).

Researchers from the University of Oxford compared 50 genes with a variety of organisms to determine where this enigmatic species fits into the animal kingdom.

There are practical implications for this as well: apparently Buddenbrockia is closely related to a parasite that causes trouble for salmon farms (I don't have time to go into my issues with salmon farming the first place, though...). Current and future studies of it will hoepfully shed light on how to conquer the parasite, although I think that the taxonomic revelations are pretty cool all on their own.

(Photo credit: University of Oxford)

Could you solve it?

Scenario: You are shown a tall cylinder with a tasty nut in the bottom. How do you go about getting it out, assuming the cylinder is too tall and narrow for you to reach the bottom, and that it is fused to a tabletop (you can't dump it out)?

Could you create a strategy for getting the nut? Orangutans in one study showed amazing problem-solving skills to obtain the nut: they took mouthfuls of drinking water and spat into the cylinder, to make the nut float within finger-grasping range.

The five orangutans tested needed an average of nine minutes to realize that they could float a peanut to the top of the container, you can see an example here:

Pretty amazing, I think! Orangs are infamous for using tools and escaping enclosures in captivity (read about the legendary escapades of Fu Manchu here), which is interesting because in the wild they have not been observed to use tools to the same degree as other apes, or to captive members of their own species.

If I could pick one primate to study it would definitely be the orangutan, there is so much about the species that is unique from the other great apes. They are so imperiled right now, though, and often from places people wouldn't expect, like efforts to promote biofuels instead of fossil fuels. You can learn more about orangutan conservation efforts here, the statistics are very disturbing.