Is the naked mole-rat an animal that actually never dies? An immortal being, just like Wolverine?

The naked mole-rat

The naked mole rat lifespan is eternal. Not that it lives forever, but it seems to age very slowly, if it ages at all.  Almost blind, and tube-formed… The Heterocephalus glaber, is an animal so strange that it defies the very laws of nature. It’s objectively hideous, but it’s a creature with a multitude of extraordinary features, a wonder of God’s creation.

They live in the horn of Africa, Ethiopia, Sudan, and Kenya, in dry, desert-like biotopes. There they dig tunnels underground. A single network can reach out as long as 3 miles (5 km). They eat tubers and they reap them from underground, so there’s no need to ever stick the head up in the sunlight. They are small, about 3 – 4“ (10 cm) long, and weigh about 35 grams. And the body is perfectly tubular. Suited to life in a tube. 

A naked mole-rat

Their family life is also out of the ordinary. Just like bees and ants, there is just one female that reproduces. To help her with fecundation she has a few male rats at her side. All the others are workers for the benefit of the cluster. The females are reproductively suppressed. Their ovaries are not fully mature. Should the Queen die, another of the females, normally the biggest and strongest, becomes Queen and develop sexual functions. This is called eusociality, and this hairless mole rat is the only mammal on earth, that has this behavior. 

The new Queen, after the coronation, slowly becomes bigger. But only in length. Growing in girth would make her stick in the tunnels. Gestation is about 70 days. After birth, the Queen feeds the youngsters for 30 days. Then they have to rely on other nutriments… They eat feces until they’re big enough to eat solid food… it’s a way to economize resources. 

Actually, also the adults eat feces, and it has a very special purpose. Tubers are hard to digest. Eating poop serves as a second digestion system, a bit like the cows and their four stomachs.  

All the weird things that this extraordinary little buddy does.

Here’s a list of all the strange qualities these extraordinary naked mole-rats have:

• They are not really hairless. They actually have a few almost invisible hairs that help them to feel the surroundings inside the tunnel. 
• Their skin lacks neurotransmitters. That means that they don’t feel pain from acids. The skin is also extremely elastic.
• They are poikilothermic, meaning that their body temperature adapts to the surrounding environment. But if the surrounding temperature rises over 92° F (28°C), a homeothermic cooling system kicks in to avoid too high body temperature. This is very rare among mammals.
• They can run as fast backward as forwards.
• One-quarter of the total muscle mass consists of the jaw muscles. 
• The teeth can move independently of each other. And the lips close behind the teeth. This is so that earth doesn’t enter the mouth when digging. 
• They sleep in any position, even belly up, upside down. 
• They are extremely resistant to foul air. They can live for hours in air with so low oxygen and high carbon dioxide levels, that it would be lethal to other mammals. It survives a considerable time even with no oxygen, using fructose in an anaerobic glycolysis process. It’s not fully understood how this is done. 

And what about their immortality? Is that really true?

Apart from all the rest, the most astonishing fact is the incredible naked mole rat lifespan. They have an almost magical longevity. The naked mole-rat can live for more than 30 years. Compared to 3 years for a mouse, and 6 years as the expected life-length considering its size. Furthermore, it has no higher risk of death as the years go by. All other animals are more likely to die the older they get. And that is from any cause… Falling, starving, biting, etc. We just die easier with age. 

But the naked mole-rat seems to be as fit and vital at 30 as it is at 2. It still catches diseases, fights with others, gets eaten, and suffers from all other kinds of disasters. But the chance of one particular hairless rat dying is the same if he’s 3 or 30 years old. It doesn’t matter. 

Researchers have studied this phenomenon in search of some crucial detail, the reason why, something that could be applied to humans, and make us live forever. 

It’s still debated, but it is believed that it has to do with its ability to reduce its metabolism when needed. And doing so, the damage from stress is prevented. Instead of hysterically trying to survive they simply shut down and wait…

And the cancer immunity?

This marvelous hairless mole rat is resistant to cancer too, although it’s believed that it’s not completely immune. The reason for this could be three-fold. 

• Living organisms have over-crowding genes. If a tumor starts its uncontrolled cell proliferation, this gene stops cellular reproduction if it gets too crowded. That way, the tumor cells can’t continue to grow. This is a very important resistance mechanism to cancer. The hairless rat has two of those genes, the p16, and the p27, and therefore a double barrier. 
• It has ribosomes that are able to produce perfect or close to perfect proteins, and thus less prone to mutations.
• It produces something called high molecular weight hyaluronan (HA). The theory is that these high levels of HA accumulate in the skin, to help it keep elastic. As a side effect, it also prevents cancer.

Conclusion

The naked mole-rat does get old. But age has no or very little impact on its physical well-being and therefore on its resistance to body failure. If it gets seriously sick, it will die. It will also die from cold, from heat, from bites, or from any other normal damage. In that way, it’s not like the Wolverine.

But the possibility that an individual dies doesn’t increase with age. It seems that a very old naked mole-rat is physically as strong and fit as a young one. They are therefore the most long-lived rodent on earth. These hairless rats live for at least 30 years. And the maximum life span isn’t known since they don’t die from old age only. 

So, although it’s not immortal, it seems to be immune to aging. 

 

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sources

• US national library of medicine
• National Geographics / Naked Mole Rat
• Wikipedia / Naked Mole-Rat
• Smithsonian’s National Zoo
• Science / Naked mole rats defy the biological law of aging

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