If you live in the UK, have you been watching the latest BBC Attenborough offering, Africa? If you answered “no”, WHY THE HELL NOT? and if you answered yes, OMIGODHOWGOODISIT??
“Sahara”, the episode that aired last night (30/1/13) has probably my personal highlight so far, not least because it featured one of my favourite funny looking creatures in the world ever: The naked mole rat.
Despite it’s appearance, this creature is not actually an old wrinkly penis with buck teeth growing from it’s nostrils.The naked mole rat is so ugly it is almost adorable. But not only does it look so goddamn horrendous that it becomes some sort of mythical being that you can’t quite drag your screaming yet sympathetic eyeballs away from, it is also a very interesting little creature, for several really cool reasons. Let’s start with its physical appearance, since we’re all judging it already. DON’T PRETEND YOU’RE NOT.
It’s hard to miss the fact that naked mole rats are, well, naked. But if you look closely you will see that they are not completely hairless, oh no. Natural selection has given them the mole-rat equivalent of a fig leaf and provided them with some lovely long super-sensitive whiskers which help them feel around, which is handy when you live in narrow tunnels under the ground (they can also run backwards just as effectively as forwards, which is also handy for the environment they live in). Because they are perfectly adapted to living in underground burrows, the naked mole rats have practically lost the need for their eyes, which are present but are located underneath their skin and are essentially useless. And who can ignore those gnashers? Like all rodents, the incisor teeth of the naked mole rat never stop growing. They protrude in front of the lips (which are sealed behind the teeth) in order to stop the critters swallowing soil when they are using their wallies to dig through the soil – all of which I’m sure you will agree just adds to their sex appeal.
Although they are mammals, naked mole rats do not regulate their body temperature the same way most mammals (including ourselves) do, through a process called thermoregulation. Sweating, shivering and panting are examples of thermoregulation, whereby an organism keeps it’s core temperature at a stable level, regardless of the temperature surrounding it. Rather, naked mole rats are cold-blooded thermoconformers, meaning that their core body temperature changes depending on how hot or cold their environment is. But because they live underground in the African desert, the habitat of the naked mole rat has a more-or-less constant temperature which is comfortable for them.
Perhaps the most peculiar thing about naked mole rats concerns their social structure, as they are one of the very few mammals which are described as “eusocial”: Eusociality is a hierarchical social structure more commonly found in social insects like ants and bees, wherein each colony (for a naked mole rat this is around 80 individuals) has a reproductive “queen” who produces all the offspring in the group, and all the other individuals are “workers” who are sterile. When the queen rat dies, some of the other females in the colony begin to develop eggs within a week of her death. Older females in the colony develop eggs first, and often fight to the death for the right to become the breeding female.
Hopefully I have convinced you that naked mole rats are more than just a pretty face. But the interesting facts do not end there, oh no. It turns out that these creatures may hold a very important secret which could lead to huge breakthroughs in cancer research: Mole rats are thought to be the only mammals who never develop cancer, and scientists have possibly found out why. Cancer is caused by unregulated cell growth, and the cells of naked mole rats poison and kill themselves when they multiply too much, thus cutting out cancer.
So there you have it. Cold-blooded, eusocial, cancer-resistant, bald mammals. Naked mole rats are awesome.
Wired: Why Blind Mole Rats Don’t Get Cancer: