HI im a biology student and im desperate for help!!! we got this assignment and its due friday and i do not understand anything about it, the teachers wont give me any time of the day, cause thats how loving they are, and im going crazy cause i cant find anything in book or the net!!! so if anyone could help me it would be GREATLY appreiciated!!! the topic is "Mammals maintain a thermal homeostasis, but they do it only by expending considerable amounts of enery. would you consider this a handicap?" So if anybody knows wat that means could you plz explain it to me??? plz?? thank you so much if you do please help me i dont wanna fail!!! ... Jezza Please Register or Log in to view the hidden image!
http://www.sciforums.com/showthread.php?t=37724&page=2&pp=20 http://www.google.com/search?hl=en&ie=UTF-8&q=thermal homeostasis&btnG=Google Search hmm looks like there is a lot of stuff out there. Is that the only question btw, because as i see it, it can be answered with a simple, no.
thank you but i still dont understand any of this Please Register or Log in to view the hidden image!
As I see it: Mammals maintain a constant body temperatur to survive, to little or to much heat are bad even fatal. Is this a handicap, perhaps, but its a required handicap. WARNING: I have absolutly no education what so ever within biology Please Register or Log in to view the hidden image!, unless you count public school
oh yea forgot to add, animals including humans are not that stupid, they us external sources or have evovled to save a maximum amout energy.
Kunax you could also identify that the likelihood that the dinosaurs died out through "perhaps" the lack of body thermals were as mammals survived kind of gives an indication as to who had the handicap. For instance, snakes and other reptiles move more when it's warm then when it's cold, If a snake was placed at either of the earths poles it would freeze and die far quicker than a mammal. Another thing to add here is that Mammals that have "Litters" tend to share their body heat with their offspring (even birds do that, until hatching), so body heat actually aids during the deciding survival period after birth.
As you hint I think there is a bit more to the dinasours dead then just bodyheat, althou it could have been a aiding factor. But it's a bit unfair to place animals out of there envirement, like the snake which is not design for the arctic. How long would a polarbear survive place in the middle of sahara. Polarbear have black skin and it's white hairs are hollow designed to absorb and direct heat to the skin. it also well insulated with blubber. All in all it so well protected they are sometimes seen rolling in the snow or bathing to keep cool. Question A naked human and a snake is trap on the north pole(-30c, good wind) , it will take 2 hour before the rescue chopper arrives, will they die or survive?, who dies first? (thougths: human go in to shock very fast if place i icy cold water, but die from drowning, how long can they last in extreme cold on land. can the snakes go dorment and survive)
i would not consider this a handicap as the ability to provide your own heat means you can be ready for hunting when cold blooded animals are still warming up. and also this gives mammals the abilty to operate in the cold meaning that they are able to gather more food nomatter what the weather is in conclusion: the amount of energy used to heat the body is easily replaced as constant heat allows them to gather more food
indeed, and it allowed also for a nocturnal lifestyle. Remember, there is no sun during the night to heat you up. Also it allows small animals to operate under colder conditions. large animals can retain heat more efficiently because of the volume law thingie. There is a handicap though. Mammals operate on the end of the temperature spectrum. That means that they always operate close to overheating (think of fever, and how a human will die if its temeperature only goes up a few degrees). For this new adaptations had to arise.
omg thank u guys so much u have really helped me to understand but if u wanna add any more thats fine by me!!! thanks so much!!!
Ironically, the human has a better chance of surviving, but dies long before the snake does. It is almost certain the snake will die however.
why do you say the human have a better chance of surviving if he dies first? Are you think that the snake will suffer unrecoverable frost damage faster, where as humans can maintain core body heat longer for vital organs.
It might be possible to revive the snake if it doesn't freeze too much. This might not be the case with the human, although there are some miraculous recoveries in cold water. But submersion in cold water is not quite the same as exposed to cold air.
There a 2 kinds of Hypothermia fast and slow, fast could be if your fell true ice, kind of luckly the mammalian diving reflex, a reflex all mammals have will kick in if you get your head under water. It's is a kind of energy saver, reducing heart rate and redirect blood away from limps to vital organs, the effect of the reflex is stronger in cold water. But then your body start to work against you by shaking and there by sending the blood away from vital organs. I think its because of the mammalian diving reflex some(very few i think) people have been lucky enought to survice, drowning in ice waters.
btw jezza88: if you have not figured it out yet, you could look up hyper/hypothermia to see the effect of what happen when thermal homestasis fails. my spellchecker had a bad case of hyperthermia
"Mammals maintain a thermal homeostasis, but they do it only by expending considerable amounts of enery. would you consider this a handicap?" to maintain a thermal homeostasis the animal has to exert excess energy, the problem with it is that if the mammal exerts too much of the excess energy they are too weak to actually protect themselves if danger is coming. for example, say you were in the freezing cold in nothing but a bathing suit, your body would start shivering to keep up your body temperature. this would use your excess stores of energy and once that's used up you would fall into hypothermia. so it's a handicap if you look at it in freezing weather, but it's not a handicap in the wild for most animals. for a human it's a handicap, for animals in their natural habitat it's a convenience because it allows them to remain comfortable if their habitat changes temperature (for instance, season changes). i hope that helped somewhat
As the monkey pointed out, mammals work at the end of the temperature spectrum. Overheating is a still a problem, althou easier to control then frezing, it remains something that some animals need to activly "control".
looked up Hyperthermia on wikipedia, interresting, from the sound of it it sounds like it goes rater fast from start to collaps. edit: interresting because i thougth it would be a slower process
Birds also do it after hatching a clutch of eggs because almost all species of birds come out of the egg with no feathers. They have to keep the chicks warm until they are fully fledged. We've raised parrots. Ideally you let the parents incubate the eggs (they take turns, birds are a lot less sexist than mammals) and you even want them to warm and feed the chicks until they're about ten days old. (Both parents do the feeding as well.) Once their eyes open you have to take over so they "imprint" on humans and grow up naturally hand-tamed. They're usually not quite fully fledged so you have to keep them in an incubator except when they're being fed. But sometimes the parents don't know what they're doing. This is common if the parents themselves were hand-raised, it's amazing how much of what we regard as instinctive parenting behavior in birds is actually learned. So you have to incubate the eggs and then you have to care for a tiny brand-new hatchling. Which is not easy, they require a formula that closely resembles the regurgitated food they'd get from their parents. It has to be exactly the right temperature or they won't eat it. You have to stick a syringe in their mouth to imitate the way the parents feed them. And they require feeding every four hours round the clock. And you have to put them in a small padded container that forces them to stay upright because if they relax and lie down their muscles will never develop. If you've ever wondered why hand-fed birds are so expensive even though most of the species aren't particularly rare any more, especially in captivity, (there are probably more hyacinthine macaws in North American living rooms than in South American jungles) it's because raising one until he's old enough to leave home is as difficult and delicate as raising a human baby.
