Think Bomb

Tuesday, December 19, 2006

Porphyria and the Biological Basis of Vampire Lore

Porphyias are inherited or acquired disorders effecting porphyrin production in the body. Porphyrins are the primary precursors to heme, the prosthetic group required for the binding of oxygen to the hemoglobin in red blood cells, the proper function of catalase and peroxidase (important to removing cellular peroxides), and the reductive capacity of cytochrom P450 (a component of the electron transport chain). There are a number of genetic mutations that can affect production of enzymes in the porphyrin pathway, any of which may lead to an inadequate supply of heme, resulting in a myriad of physiological problems. The symptoms often include:
* Light sensitivity
* Neurological attacks- seizures and severe back and abdominal pain
* Mental instability- psychosis, hallucination, and paranoia
* Receding gums leading to a fanged appearance
* Increased hair and nail growth
In addition to all these hardships, in the Middle Ages some porphyrics took to drinking blood, as modern treatments were not yet available. Although inefficient, in large enough quantities the additional heme in the blood-based diet could reduce symptoms.

Does this not sound like the fabled creatures of the night? Perhaps it does not describe the dashing and frightening Dracula, who is believed to be based off of Vlad the second, the brutal Hungarian king also known as "Dracul" (the dragon), but it does describe a more eerie creature of legend. The German adaptation of Dracula, Nosferatu, may have borrowed some from the poryphyria-based lore to create their own variety of vampire with elongated nails and hair, rotting flesh, and rat-like features. Not nearly as glamorous as those vampires popularized by the modern novelists like Anne Rice, these "vampires" had a more gritty lifestyle, often ending in pain and insanity. They were based off of a a tragic disease, for which there was no cure.

Luckily, today there are better treatments available for people with porphyria. Hematin and haem arginate are used to treat acute porphyria. If given early enough in an attack, they can limit the nausea, seizure, and neuropathy. In most cases of porphyria, direct heme injections can help relieve disease symptoms as well.

Juan, Stephen (2006). The Odd Brain: Mysteries of Our Weird and Wonderful Brains Explained. Andrews and McMeel Publishing.
Wikipedia (2006). "Porphyria."

Monday, December 11, 2006

Nice guys finish last...not

Old school naturalists had a bad habit of anthropomorphizing—that is, they projected themselves in the animals they studied. Maybe it was the time they got sand in the face at the beach or just general insecurities coming through, but eventually we ended up with scores of literature talking about male aggression and how this is the key to mating success in the natural world. Basically, the males of the species duke it out, and whoever wins gets to mate with all the females. The idea that "nice guys finish last" underscored many accounts of natural mate selection.

This may be so in some species (lions, elk, etc) but not all. In the bird realm, it is often the female that chooses her favorite mate. It's not always skill in a fight that the ladies look for either—nest building, song, and child rearing are common factors in mate choice. One only need think of the affectionate love bird or the tender chickadee to realize that birds can have non-violence based mate selection. Still, this does not stop us from thinking of raging hormones and hostile brawling when considering species more closely related to ourselves. We imagine gruesome ape on ape battles and jump to the conclusion that there must be an evolutionary basis for the theory that "nice guys finish last."

But do they? Really? Recent studies by more primatologists have revealed a little known secret among old world monkey troops, especially baboons--female mate selection in which the nice guy gets dibs. Admittedly, it's not easy to choose your mate when you're a baboon. Typically, the males are much larger than the females, so she's easily overtaken. As another complicating factor the female baboons (and many other old world monkey females as well) can only mate when in estrous, at which point a lot of mating has to happen in a short amount of time. Baboons are certainly not monogamous, the females mate with whoever happens upon them when in estrous. Since they are only sexual at certain times of the year, the guys go back to being "just friends" without a hitch for the rest of their cycle. A funny thing researchers have noticed though is that the females don't always just default to the "top dog" of the troop for their mating needs. As risky as it may be, they will often sneak off to be with their less aggressive, lower ranking male friends. It's the baboon who grooms her, hangs out with her, and helps her take care of her young when she's not in estrous that she most wants to mate with when she is. Some females will get very clever to distract the dominant male to sneak off with her less aggressive friend. A common strategy is to pass by the dominant male's rival in an attempt to initiate a fight so that he'll be too busy to mate with her. This may result in some displaced aggression on the poor female later, but it seems that many baboons think it's worth it, just so that the nice guy can have his day in the sun.

Robert Sapolsky- Monkey Love