If we are mammals---

[keyholekatebaron]

Why don't our teeth keep being replaced like whales and sharks? Am I just thick(I've led a sheltered life please don't shout at me)xxx

[HowardKennitby]

sharks are not mammals

[RATTER15]

I think you may find more than just the one difference between different mammals :)

When did you last see a whale with a full head of hair?

[HowardKennitby]

and not all whales have 'teeth' and I am not sure that the teeth of those who do are continuously replaced.

[mightyWBA]

Well a shark isn't a mammal but I get your point..

Perhaps it's because they can't hold a toothbrush.we can and if we don't bother brushing our teeth it's our own fault they fall out :-)

[seadogg]

Not a biologist but I think our teeth evolved to last our lifetime and would not need to regrow. Of course, we now live so much longer and eat a different diet so they dont usually last the course.

[LoftyLottie]

http://www.pollingerl...olden/hairy_whale.jpg

[d9f1c7]

Well sharks, are not mammals and most whales do not have teeth. Most mammals have teeth for life (some have milk teeth of course), the configuration of which depends on their designated food groups.

[wildwood]

There is a limit to how many teeth can be replaced. Elephants for one, have a sliding system where the molars are replaced from the back to replace the worn ones. This only happens 5 times so older elephant will eventually die of starvation if not earlier from other causes. Sharks also only have a certain amount of replacements but they have more replacements than humans because that is required in the way they attack prey.

Most mammals have a juvenile set of teeth which is replaced as they grow up. A very young mammal with 'adult' sized teeth would not be able to eat, so the permanent pegs only appear when the body is larger. Humans already experience the onset of replacement molars later on in life with the appearance of the so called wisdom tooth. Unfortunately, they are rarely functional and not always develop properly.

Don't forget that the human body is only designed to last 40 odd years and without eating processed foods.

[Old_Geezer]

The human body isn't designed.
At least no designer has stepped forward to claim the accolade.

[mibn2cweus]

The distinguishing characteristic of mammals is that they have muguppies, although male muggupies most often develop much later in life than their female counterparts . . . which typically blossom much earlier into full blown bazongas.

http://www.earthlife.net/mammals/mammal.html

[wildwood]

Alas mibs... monotremes have no muguppies as such. Their mammary glands have no nipples and emit milk through slits in the skin, which is licked up by the young.

[beso]

Mammary glands have evolved from sweat glands.

[McMouse]

My dad was a mammal and he had his teeth replaced several times.

[squarebear]

lol mouse :-)