“Naked mole-rats are like the Rolling Stones”

Dr Chris Faulkes is an expert in evolutionary ecology and naked mole-rats are his thing. He works on social evolution in mammals at Queen Mary University of London. To tie in with Season 01: THE BIG BANG, TOPIA asked Richard: What will be the last creature on Earth? Here’s his case for the world’s strangest mammal – the naked mole-rat. These (almost) immortal “penises with teeth” live in a world that’s closer to Game of Thrones than you could ever imagine.

Dr Chris Faulks’ 3-minute noodles

“Naked mole-rats could certainly survive an apocalypse. They naturally live underground in nuclear fallout shelter bunkers and so they’re in survivalist mode naturally.  

Naked mole-rats are like the Rolling Stones. They’re survivors. They’ve been on the planet for between 20 and 30 million years, so they’ve already outlived many other species. If they were a band, It would be a band that has survived many generations with strong and feisty females. Now that might be the Slits, but probably more like the Stones. 

They’re suited to extreme underground environments. Living underground is a good strategy because you’re out of the way of predators in a stable environment. But if we humans were to go underground, we’d get another set of problems, because it’s energetically expensive to travel underground. Anyone who lives in London will know how much energy it takes.

They can cope with hostile conditions. Naked mole-rats don’t really need to come up to the surface at all and can survive in really low oxygen – up to 18 minutes without any oxygen whatsoever, which is pretty astonishing for a land-dwelling mammal – and they can also survive when there is high CO2 in claustrophobic tiny underground tunnels. 

They could help find the cure for ageing. They live a hell of a long time for a small mouse-sized rodent. Astonishingly, the record is a 37-year old naked mole-rat that lives in a lab in California (that’s ten times longer than a mouse). A substance in their wrinkly, stretchy skin may contribute to their cancer-resisting properties. If we can understand how they maintain a long health span, it can help humans live forever, if that’s your sort of thing.

They don’t need many calories or water. They just need some roots and tubers to get moisture from, because they don’t drink. If the whole world became a semi arid desert, as long as they’ve got some local plants in the habitat, they’d be fine. They have a very low metabolism and don’t need too much energy. Because naked mole-rats live in an extreme underground environment, everything’s just gone crazy with their biology. Today they can be found in East Africa in the arid regions of Kenya and Ethiopia and Somalia. 

They’ve evolved into an unusual social insect-like lifestyle. Bees, ants, wasps and termites live in a society with overlapping generations of helpers that help to raise the offspring of a breeding individual. Other mammals do it to some extent, like meerkats. Humans also have a grandmother effect, where we carry on living after menopause, and the next generation helps with the rearing of offspring.

They are socially tolerant and form bonds and affiliations. Your brain has to be wired up in a particular way in order to be able to live together! Rather like humans today, living in London with kids who never disperse because they can’t afford to go, these mammals have a predisposition to live as a family and tolerate one another.

Their queen rules society. You can’t have everybody reproducing like crazy because there won’t be anyone doing any work. So the queen mole-rat is the only female that breeds. More than 99% of the naked mole-rats in a colony never go through puberty. As cooperative behaviour evolves, she suppresses reproduction in all of the others of both sexes, except for up to three males who she has a long-term monogamous relationship with. Breeding females can reproduce well into old age, indeed one female is known to have reared more than 900 offspring. We’re still trying to unravel how the queen suppresses everyone so entirely. 

Their whiskers are important sensory information providers. They might be furless but do have a smattering of sensory whiskers over the body which gives them an important tactile sense. While living underground in total darkness, a sense of touch is critical.

They pile up to reduce their energy. Naked mole-rats huddle together in massive piles to maintain a constant body temperature. In the wild it is possible to find up to 300 animals in one colony. The nest chamber looks pretty scary when you see it, but they’re in a blissful state when they take power naps on top of each other. 

They do seem to be happy. They’re very motivated to do their roles within the colony, digging away and sweeping up – busy doing their mole-rat thing. They don’t mope around looking depressed and feeling ill.

They don’t seem to die. If you plot mortality against age, the older you are, the more likely you are to die. But naked mole-rats don’t follow that trend. They do have predators in the wild in the form of snakes and birds of prey could grab them when they’re making their little mole hills. But we are still really trying to find out what their end-of-life pathology is. Until 30 they do well, and then they go downhill with organ failure really quickly, like a sort of Dorian Gray. There’s probably lots of portraits of mole-rats stashed away in their burrow system somewhere!

They’re enigmatic. Whenever we think we know everything about them, someone finds something else. We know they run backwards and have teeth that move independently like chopsticks, but colleagues in Germany published a paper recently that suggests each colony has its own dialect in a certain chirping noise. Imagine them all having slightly different accents! Amazing. 

If everything came down to a Celebrity Deathmatch, they can be very aggressive. Even though they’re vegetarians, a mole-rat could eat a tardigrade or cockroach. They live in a harmonious, slightly utopian looking society but there’s a lot of competition. If you play the Game of Thrones, you win or you die – and that’s how naked mole-rat colonies operate. The queen dishes out aggression, keeping everything in order and attaining her position by fighting to the death. There’s also a bit of inbreeding going off as well, so that’s very Game of Thrones.