Cetaceans are the largest group of hairless mammals, made up of animals including whales, dolphins, and porpoises. This makes sense, as hair isn't very helpful for an aquatic lifestyle. Instead, these creatures insulate themselves with a thick layer of blubber.
Most mammals have hair which can vary greatly in color, length and texture (Pough et al., 1989). However, there are several so-called 'hairless' species – such as whales, walruses, elephants, and humans – that have considerably less hair than other mammals.
Hair (and a coat of hairs, called fur or pelage) is uniquely mammalian. No other creature possesses true hair, and at least some hair is found on all mammals at some time during their lives. Hairs grow out of pits in the skin called follicles.
The easy answer is that; hair is an insulator (keeps heat in), and elephants and rhinos are big ie they have less surface area compared to volume. Hence, they have less surface area to get rid of the heat produced by their volume.
According to the scientists, being hairless has its own evolutionary benefits. For instance, without dense hair, elephants cool off more easily in hotter climates and walruses glide effortlessly in water.
Whales and Hippos Evolved Water-Ready Skin Independently
They also share characteristics that are odd for most mammals, including smooth, nearly hairless skin that lacks glands that produce an oily substance called sebum that lubricates skin and hair for most land mammals.
In fact, approximately 98% of all mammalian species do not menstruate [1]. Menses is almost exclusively restricted to higher order primates, which include humans, rhesus macaques and baboons, with the only exceptions (until very recently) being a minority of bats [2–5] and the elephant shrew [6].
Why do humans have pubic hair, when other “hairless” mammals, like pigs and elephants, manage without it?
Elephants have breasts, like humans, and not udders like cows. Their breasts are between their forelimbs on the 'chest' of the elephant and are only visible once the elephant has had her first pregnancy, until then male and female elephants look similar.
The skin in the area around the genitals is very sensitive. Pubic hair can naturally reduce friction associated with the movements during sexual intercourse and other activities wherein chafing may occur. Pubic hair can also help stop bacteria and other microorganisms from entering the body.
All spiders are hairy - like us. Spider hairs are part of the hard outer cuticle (the spider's 'skin'). Unlike us, spiders use their hairs (which are often greatly modified) to perform an amazing variety of tasks - for sensing their world, in courtship displays, for moving around, and in defence and prey capture.
The only mammals that don't have nipples are those belonging to the group known as the monotremes – these include the duck-billed platypus and the echidna (both of which lay eggs rather than birth live young). While they have mammary glands, the milk just sort of dribbles out of tufts of fur.
Hippo skin is 6 cm (2.4 in) thick across much of its body with little hair. The animal is mostly purplish-grey or blue-black, but brownish-pink on the underside and around the eyes and ears.
They are actually a type of fish. Unlike mammals, sharks don't grow hair, produce milk, or have a neocortex (part of the brain involved in perception and thought, among other things). Instead, like other fish, sharks have gills, are cold-blooded and are covered in denticles (tooth-like scales).
If you're allergic to fur and feathers, you can always resort to scales. Snakes, turtles, tortoises, and lizards of all kinds – all of these pets are non-allergenic but still offer a great deal of fun. Large and small, legged (lizards, turtles, tortoises) or legless (snakes), nocturnal or diurnal (active at night vs.
Our hair loss is thought to have happened well before modern humans migrated north of Africa. So body balding would also have allowed our ancestors to better control body temperature in hotter climes. You may need a coat sometimes, but at least you don't have to carry it around all year long.
In human eyes, there are cones for red, blue, and green, making us “trichromatic.” It has been said that color-blind humans share identical sets of visual pigments with elephants, meaning that they can see the colors blue and yellow but reds and greens are not distinguishable.
They might kiss on the cheek or hand. And they might give a nice big hug.
Elephants do grieve, and they are one of the few animals who are similar to humans in mourning patterns. Believe it or not, elephants cry.
Hairy armpits are clearly evolved to collect pheromones and, as we know, the sweat we secrete in our armpits is quite different to the sweat we secrete over the rest of our bodies.
It's a process by which mammals that have uteruses will shed the lining and unfertilized eggs. What's interesting is that unlike most other mammals, guinea pigs do not menstruate during their reproductive cycles!
Pigs are checked for complete unconsciousness before being slaughtered quickly and painlessly with a sharp knife. While pigs are unconscious, they do not feel pain. They are then bled out, dying humanely without regaining consciousness.
Myth: Animals can smell your period blood from miles away and will attack you. Fact: There is no evidence at all that sharks, bears and other animals are attracted to period blood. It's completely safe to carry on swimming in the sea or camping while on your period.
Do other animals have belly buttons? Because the navel is a scar from where the umbilical cord connected the fetus to the placenta, all placental mammals have them. That includes all mammals except marsupials (like kangaroos and possums) and monotremes (like platypuses and echidnas).