Why don't naked mole rats have fur or hair?

Question

All mammals are supposed to have some kind of hair or fur, and marine mammals lost it because they're more streamlined without it, but why did naked mole rates lose their fur? How are they better off without it?

Answer 1

Naked mole rats (Heterocephalus glaber) are not only fossorial (diggers) but also live underground permanently, and, more strikingly, they're eusocial. This means that they live in colonies analog to those of ants or termites, in which there is one dominant reproductive female (the "queen") and the rest are workers that don't reproduce, but are continuously expanding and maintaining the burrow system.
They're highly specialized in a number of ways, and their skin is no exception. They lack fur, but have a thicker epidermis and very few sweat and sebaceous glands; the dorsal skin also lacks hair follicles. Due to these characteristics, the skin lacks an insulating layer and heat transfer with the environment is enhanced. Thus, their body temperature changes according to environmental temperatures, and they're physiologically poikilothermic (like lizards or turtles).
They obtain heat from their surroundings by thigmothermy (heat conduction from the surface of rocks, soil, other individuals, etc). The temperature inside the burrows is more or less constant (32-34ºC), and in fact, the colonies are so crowded that they're moving very close to other individuals all the time. If the heat loss increases, they huddle together (huddling behavior).

So, although the history of the loss of fur in these animals is not known and can only be hypothesized, it is clear that they have compensated for it with skin and behavior specializations.
And it works.
Evolutionary biologists must start from that premise, in order to reconstruct evolutionary processes. This particular history is not known (at least to me), and not easy to reconstruct because hair is not preserved in fossils, but remember that not all explanations must be adaptive!
Adaptive explanations always come "a posteriori", and all evolutionary events have also an aleatory component.

Oh, and the naked mole rats do indeed have some fur, mainly tactile hairs around the face and tail, between the toes, and some scattered bristles.

I know I did not answer your question, but I wanted you to know why it's not easy to answer.

Answer 2

This one is easy. There are mole rats that do have fur. It depends on where they live. If the ground can get cooler then fur is good to have to keep you warm. Naked mole rats live where the ground stays warm so fur isn't needed to maintain body temperature. The reason why they don't have fur is the same reason why bird species become flightless when they don't have predators. It takes a certain amount of protein to make hair or fur (and also claws or nails). If you don't need this then your body can conserve protein by not making it. Naked mole rats eat a diet that is low in protein so this is a benefit to them to be naked.

With birds, the body must be kept light and the wing muscles strong to be able to fly. When there are no predators and no migration bird species become less and less capable fliers because it is easier to have a non-flying body. Large wing muscles burn up calories even if you don't use them.

Answer 3

Marine mammals have hair. They are tiny hairs which are really hard to spot but theey are stil there. The naked mole rats do have hair but just a little bit because when they are underground the sand and dust will get stuck if they have a lot of hair and its really hot in the desert.

Answer 4

Naked mole rats still have hair. Just not very much. Some reasons they may have lost their hair:

1) it's might be more difficult to dig and move around in tunnels with hair.

2) generally the temperature underground doesn't change much, so they don't *need* the hair. It's a waste of calories to make it.

See the at the link below.

Answer 5

All mammals have hair or fur you might not be able to see it though, even marine mammals. So those moles have some hair somewhere.

Answer 6

because they spend more than 90% of their lives underground, it makes sense. Because of their fossorial life style, they are prone to be dirty, not having hair help avoid this situation.
Because they live underground, the temperature is pretty constant....in Africa, its pretty hot, in order to maintain homeostasis and thermo regulate, they have lost their fur, this makes it easier for them to cool down.

Answer 7

Because they're stupid hippy nudists. They need to get a clue and put some damn clothes on. They make me sick!!!!!!!!!!!!!
They should be called stupidhippynudistwhoneedtogetaclueandputsomedamnclothesontheymakemesick mole rats.

Answer 8

if they did, they wouldn't be nekkid! couldn't resist.

They are desert animals and don't need the fur. Also they, live underground and it is not practical.

try this link:
http://nationalzoo.si.edu/Publications/ZooGoer/2002/3/nakedmolerats.cfm

Answer 9

Probably dug too deep in to a radioative site.

Answer 10

They probably do, its just very thin and light.