You could be forgiven for thinking that the idea of teenage turtles who mutate into humanoid ninjas is a tad far-fetched. But you may be shell-shocked to learn that actually, in reality… it is.
“First of all,” says Jeanette Wyneken, professor of biological sciences at Florida Atlantic University, “the chromosomes of a turtle and of a human don’t match up. Turtles have more chromosomes than we do. And if your chromosomes don’t match up, you often end up with genetic abnormalities called a ‘teratology’, a term that literally means monsters.”
But let’s ignore all of that. Let’s suppose, somehow, there are mutant turtles that stand on two legs and say things like, “cowabunga, dude”. Would their turtle physiology be able to adapt to humanoid anatomy?
“One big change,” says Wyneken, “is that their centre of gravity would shift from their shoulders (while on four feet) to their hips when they stand on two.” For a conventional four-legged turtle, this would mean toppling over from the weight of their shell, but “for humanoid turtles it’s not much of an issue,” says Wyneken, “because it would be more like a human wearing a big backpack.”
The major difference, however, is that when a human wears a big backpack, that backpack doesn’t also contain their ribs and spine. Whereas with turtles, the vertebral column is part of the shell; they can’t take it off. According to Ivana Lezcano Serra, Wyneken’s graduate student researcher, who specialises in turtle shells, this fact makes the new animated film Teenage Mutant Ninja Turtles: Mutant Mayhem difficult to take seriously.
“In the trailer, they’re jumping around and doing all of these acrobatic stunts. But that fusion between spine and shell would make that very difficult,” she says. “They simply wouldn’t have the kind
of flexible spine that would allow them to do backflips.”
So they can’t be mutants and they can’t be ninjas. Can these turtles even be teenagers?!
“The new movie really focuses on the fact that they’re young teenagers,” says Lezcano Serra, “and that poses a problem for their abilities. The older turtles get, the more developed and ossified their shell becomes. They have more mineral in the bone. Younger turtles – their shells aren’t going to be as hard. It’s not going to protect them as much as they would probably want.”
Even as adults, their shells wouldn’t be bulletproof, says Lezcano Serra. “They’re not like Captain America’s shield. Shells protect turtles against things like shark attacks, but what a lot of people don’t appreciate is that it isn’t through strength, but flexibility. Steel can resist forces 1,000 times better than a shell can. A shell is more like a squeezy ketchup bottle: it deforms and then gets back into shape.”
This flexibility not only applies to their shells, but also to their diet and environment. Red-eared slider turtles – the subspecies that the TMNT were originally based on – “can live just about anywhere there’s water and food,” says Wyneken, including the sewers of New York. But what of the teenage turtles’ favourite food, pizza?
“Red-eared slider turtles eat a variety of things,” says Wyneken. “The cheese may not be great for their digestive system. The carbs in the crust? Maybe in limited quantities. The vegetables would probably be fine. Turtles will eat tomato; just don’t give it to them in the form of pizza. Could they eat pizza and survive? I think so. Could they eat it and be healthy? Not in the long run.”
About our experts
Jeanette Wyneken is a professor of biological sciences at Florida Atlantic University. She is expert in vertebrate morphology, physiological ecology, behavioural ecology, and marine conservation biology. Her research on sea turtles has been published in journals including the Journal of Herpetology, Endangered Species Research and PLoS One.
Ivana Lezcano Serra is a graduate student pursuing a PhD under the guidance of Prof Jeanette Wyneken. During her master’s research, Lezcano Serra investigated how incubation temperatures affect the cognitive ability of loggerhead sea turtles.
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