What if Twilight were Real?: On Vampires, Part-Humans, and Hybrids

I don’t like Twilight. I don’t like it because it’s the most poorly written book series I’ve read in a long time. I roll my eyes at all the people going nuts about the new movie that just came out. But I’m not going to get into that here. This is a science blog, so I’m going to attack it from a purely scientific standpoint: is this world possible? What biological facts has Stephenie Meyer ignored in order to create her vampires?

I guess I should say that this post contains spoilers, although I doubt that applies to anyone reading it. There’s no in between with Twilight: either you’ve already read the books and seen the movie, or you have no intention of doing so. If you don’t know already, this new movie involves a vampire (Edward) and a human (Bella) having a baby together. It even makes a feeble attempt to explain how this could happen, which needless to say falls a bit short. Let’s take a look at how this could work:

The 23 chromosomes of a human female.

Humans have 23 pairs of chromosomes. Vampires apparently have 25, according to the book (yes, I read it, but no, I didn’t like it, so that makes it okay, right??). This is preposterous. All vampires used to be human, and transformed into something more otherworldly when bitten. That means that during the changing process, while the vampire venom was racing through the victim’s veins, all of the soon-to-be-vampire’s cells sprouted 2 extra chromosomes. Now, cells can and do change throughout a person’s life. They respond to chemicals in their environment. There are several examples of this; for example, hormones can do things like tell your cells to take up sugar from the blood and store it (insulin) or encourage certain tissues to develop (testosterone), and neurotransmitters carry signals from cell to cell in your brain and nervous system. However, the formation of new chromosomes out of nowhere just isn’t gonna happen. It actually can occur in a species over time, but having new DNA spontaneously pop up in every cell in a single organism all at once? Nope.

Okay, whatever, we’ll just assume that vampire DNA is magical, because why not. However, we have another hurdle: humans and vampires would probably be considered different species, which causes problems when it comes to mating. Different species often don’t mate with each other, because it’s actually a bad thing: some of a species’ unique characteristics (including traits that help that species survive) may be lost in a hybrid. There are several things that work to circumvent this problem by making sure different species are isolated from one another (although, in this case Edward and Bella are creatures capable of rational thought and can work around these differences. Or Stephenie Meyer sucks at biology. One of the two.):

• Habitat isolation: Edward gets all glittery in the sun. He can’t have humans know this, because then he’ll be constantly bombarded with people asking where to get tickets for the Ke$ha concert, so he needs to hide on nice days and live in dark, rainy places. He doesn’t live in the same way or the same places that humans do, so he shouldn’t ever cross paths with them. (But he chooses to do so anyway because he … wants to go to high school? Even though he’s already been to both high school and college multiple times? I don’t get it.)

(Via Flammietta's Photobucket)

• Sexual or behavior isolation: Edward wants to get Bella a present. What should it be? Here’s one possible scenario: the female vampires Edward knows love to get vials of yummy blood, so he gets Bella one. She’s grossed out and leaves him. Luckily, Edward’s done his homework and knows that female humans prefer gifts of yummy chocolate. In the wild, though, animals may not be as in tune with other species’ mating rituals, and they’re more likely to strike out on the first date.
• Mechanical isolation: Often, a member of one species has junk that just doesn’t match up with the junk of another organism. I actually would think this would be the case for our vampire-human couple, seeing as Edward is, er, really cold — cold enough that his skin is uncomfortable to the touch. But our unconventional couple solve this problem by changing habitats: they honeymoon on some remote tropical island, where it is very hot and Bella’s going to want to … cool down.
• Gametic isolation: Even if members of two different species are able to hurdle these outward obstacles and get it on, there are more problems: the two sex cells (the egg and the sperm) may simply be incompatible. All the ingredients are there, but the cells can’t fuse and the egg just doesn’t get fertilized. I am unfortunately not knowledgeable enough to speak about the fundamentals of vampire sperm, so here I can’t speculate.
• Genetic isolation: Okay, so against all odds (and against several rules of nature) we have a fertilized egg. There may still be problems. Because humans and vampires have different numbers of chromosomes, and presumably have different genes, and there is a good chance that these genes would not be compatible with each other, leading to death of the hybrid fetus.

Even with all of these barriers, members of different species do sometimes mate successfully (although this doesn’t mean Stephenie Meyer is off the hook). The most common is probably the mule (horse+donkey), but there are several other examples of this:

• Zebra+Donkey=

Zeedonk/Zeebonkey/Zeebrass

• American Bison+Cow=

Beefalo (The meat is lower in fat and cholesterol!)

• Polar bear+Grizzly bear=

Polizzi Bear

Um, I mean:

Pizzly bear/Grolar Bear

• Wild grasses+More wild grasses=

Wheat (yup, it's a hybrid)

• Griffin+Horse=

Hippogriff

Er … that last one may not be entirely real. But I hate to be the one to tell you, vampires aren’t real either.

One final thing: who gets the awesome job of naming these hybrids? Turns out there’s actually a system for this, according to www.messybeast.com: the daddy’s name goes first. So a male lion and a female tiger have a liger, while a papa tiger and mama lion have a tigon. Unfortunately for Napoleon Dynamite, however, neither of these is bred for its skills in magic. Leave the creepily magical hybrids to the obsessed, glittery vampires and their vapid, absurdly klutzy girlfriends.

Napoleon Dynamite's Liger

(Beefalo image via www.ansi.okstate.edu, Snooki image via www.dailymail.co.uk, Harry Potter book image via http://harrypotter.wikia.com, Liger image via http://blog.zap2it.com, all other images via Wikipedia)