why is it that mammoths had hair but elefants dont?
465233
For elephants living in warmer climes, hair would be a distinct disadvantage.  With a critter that size, one of their main challenges is actually getting rid of body heat.  That's why African elephants have such large ears, so they can radiate away some of their excess body heat.\n\nWoolly mammoths (Mammuthus primigenius) thrived during the cold periods at the height of maximum glaciation, particularily in areas such as Beringia, Alaska and Siberia that would have been hyperarid and bitterly cold much of the year.  There, having a thick coat of woolly hair would have been a definite advantage, allowing the mammoth to survive in conditions of -40 degrees quite happily.\n\nIt is possible that not all mammoths were as woolly.  There were other species, such as the Columbian mammoth (Mammuthus columbi) which was found in the southern United States and down into Mexico, that seem as though they might have been better adapted to the warm interglacial periods.  These mammoths may have looked more like the modern elephants, only bigger (one tusk uncovered in Texas was close to 5 m long).
594696
Assuming you mean - in general why do elephants testis etc. not hang away from their body.\n\nThe answer is basically because it prevents them from being damaged while walking (being dragged), or from predators leaping up towards the animal.\n\nBecause we stand on two legs we're more readily prepared to fight whatever comes at us from the front.\n\nOther animals on fours have no underbelly protection so they pull in the testis in an adaptive way which basically protects their species ability to reproduce.\n\n\n----\nHope this helps you.\nEnjoy zoology, I hear it's terribly hard.
1115360
The simple answer is, of course, different anatomical adaptations. Since water helps support the whales mass, their skeletons are relatively light compared to a land animal's. The dinosaurs had made many adaptations to their weight -- just as elephants, hippos and rhinos have.\n\nThat said, a small fall for a creature of large mass is likely to do internal damage in a way that never happens for small animals.
853201
Because they have fur or feathers.
35217
Just like insulation in homes, and your mom telling you to wear layers, hollow hairs trap air which holds in heat better.  The animals with the hollow hairs will be found in cold climates.
74539
Your eye brows (that you probably pluck) are there to protect your eyes from blinding sunlight, dust, and sweat.  Your nose hairs (which you probably don't even know you have) help filter out debris from entering your lungs.  If you are a woman, the hair on your head believe it or not attracts the attention of men.  As for the rest of it, well...,depends on your personal beliefs.  I think that we are primates, which are all hairy.  All mamals have hair, even dolphins and whales.
603296
During the ice age, mammoths were hunted by both neanderthals and modern humans for their meat, fur, and tusks. This helped cause extinction of the woolly mammoths. Further more, after the last ice age, the mammoths couldn't cope up with the new environment, because they had too much fur.
228732
Interesting question, but I think you're putting the cart before the horse. \nI could say that they don't live out of the water because their many specializations make it impossible; you've seen what happens when a whale gets beached. \n\nAnd why not turn the question around? Why not ask\n"If dolphins live in the water, why do they have lungs instead of gills?"\nThe thing is, adaptation is a phenomenon that usually shows us amazing results, such as the entire lifestyle of cetaceans (and they have many specializations for aquatic life). But a specialized or well-adapted animal is not "perfectly" fitted, because of the way evolutionary processes work. \nEvolution and natural selection can only work on the "materials" that are already there; and the lungs of mammals are not something that can be "reverted" to gills; their origin goes way back to remote ancestors of the whales. This irreversibility of _complex_ evolutionary processes is known as Dollo's "law" (and creationists love to misinterpret it). Stephen J. Gould gave a good example with the giant panda's "thumb" (this additional finger arose from one of the bones of the carp (wrist), and the real thumb of pandas is as reduced as in the rest of the Carnivora). \nEven if cetaceans where to evolve back into terrestrial animals, the results would not look like their ancestors, or probably anything that we know.
160576
I suppose all eutherian mammals should be considered higher, (excluding metatherian and protherian). Any other division would be very skewed ,a hypothetical elephant looking for higher mammals would view evoloutionary history in terms of proboscitude ;pthus considering all mammals with larger noses then average as 'higher'
25918
There are a lot of kinds of "hair". Each species of mammal has at least one kind of "hair" or fur. Many species have several different specialized types. For example, cat whiskers are very different from regular cat fur in texture and length. One of the main differences in hair is whether it is determinate in length (grows to a certain length and stops) or indeterminate in length (grows for as long as it is alive.) Humans have both kinds in different places on the body. Head hair, scalp and face, is indeterminate. Body hair, arms, underarms, legs, pubic area, fingers and toes is determinate. The only determinate hairs on the head are normal eyebrows, ear hair and nose hairs. I think the reason is obvious. "Wild hairs" are determinate hairs that have encountered a genetic failure. The length possibilities of each type of hair from sheep's wool to seal fur are genetically determined.  Pubic hair is a secondary sex characteristic that signals availability for mating. It is not designed to cover, conceal, protect, or warm the area that produces it. It may have some scent retaining or focusing function too. This is still debatable. I hope this helps.
245236
Horses have genes, and those genes determine what the horse will look like.  If there wasn't genetic variation, all the horses would look the same.
115450
No, definitely not. So if you've found hair in an anchovies can or something like that, it came from a mammal. Yeugh.
206614
some animals were them on the outsied insects and lobsters.\ninvertabreas dont have a spine and some dont have any bones!
553375
False. All creatures, from worms to humans, have specialized cells.
263149
THeir fur is actually colorless, it absorbs light to heat their bodies.  It works so well, that they frequently have to swim in freezing waters to cool down or roll around in the snow.  They aren't very active either becasue then they would overheat.
244658
African elephants are larger they have a concave back, and their head is the highest point. Their ears are also much larger than the Asian elephants; they are in the shape of Africa and the Asian elephants are in the shape of India (with some artistic license of course). African elephants have larger tusks and two protruberences (fingers ) on the end of the trunk vbersus one in Asian elephants.\nAsian elephants heads are more domed and less angular.Their convex back is the highest point .\nEdit:African elephants ears are not larger to protect them from sand as someone said below; they act like large raiators to loose or gain heat quickly
17910
Because species are defined by the ability to interbreed and produce viable progeny that can still breed.  A horse and a donkey can mate to give a mule, but the resulting mule is sterile.\n\nA better question is why dogs and wolves have different names scientifically.