what / who determines the length of life of a living creature?
539260
The living creature itself and the environments surrounding it.
316138
You are asking two very different questions here, and I will address each seperately.\n\n"Are, Say, Giraffes More Evolved Than, Say, Squid or Amoebas?"\n\nNo. All life currently on Earth has had ancestors evolving for the same length of time, as all life shares a common ancestor. You might argue that the more generations something has been evolving, the more 'evolved' it is, in which case, bacteria like E. Coli are the most evolved. I consider generation length to be a function of evolutionary adaptation, so I would say that between two organisms which are alive at the same time, neither is more evolved than the other.\n\nAs for your second question,\n"Are some organisms more "advanced" than others?"\n\nSure. It all depends on what you mean by "advanced". Eukaryotes are certainly more complex than prokaryotes, for example, so if you defined "advancement" as "number of cells", then blue whales are probably the most advanced organisms. If you define "advancement" by the number of cell types, well, I have no idea what's the most advanced, but it might be "mammals" or something; regardless, it's probably a pretty big group.
489172
1- large amount of offspring in shorter time than K selected species.\n2- Early reproduction \n3- low biomass\n3- short lifespan\n\nBacteria, mice, insects... they're all r-selected.
5940
The length of hair and all other aspects of cell growth and type of cell is based on DNA.\n\nDNA is the code of life. It also determines the specific characteristic of your family traits through Chromosomes passed on by your parents.
1089146
I'll stay strictly biochemical, and not consider teliology or evolution, since the previous answerer addressed some of this.\nThough there is a hypothesis that aging and death occur because of damage, oxidative stress, etc, there is actually very little data to support this-in fact, the information we have explicitly argue against this.  Rats, mice, etc, live only 2-3 years, and show cellular degeneration, etc, very similar to that seen in aged humans, and yet are not exposed to greater levels of oxidative stress, or indeed extra stress of any kind, than humans.  If it truly were a matter of stress exclusively, the range of survival times would tend to be much broader than what we see- IN other words, some humans would die of old age at 5 or 6 years old, and some would live to 200-300 years old.  Stress, oxidation, poor diet can indeed influence the age at which we die, but they are not the primary determinants... it is apparent that this is a genetically controlled phenomenon, and that it occured soon after the rise of multi-cellular organisms, and that it varies greatly between species.  There have been some senescence genes found, that are specifically turned on that seem to guide cellular damage-however, it seems as if the greatest portion of the aging process, developmentally, is caused not be production of completely new proteins which end up killing us, but by variations of levels of proteins already expressed- For instance, there are significant decreases throughout life in a number of hormones, including androgens (in men) growth hormone, insulin-like growth factors, various neurotrophic factors, etc- and a concomittant rise in others, especially pro-inflammatory hormones, such as TNFa and certain interleukins.  All of this is genetically and developmentally regulated to a fairly specific time, and is slightly variable depending upon diet, exercise, etc- It is similar to the timing of puberty, which is primarily set as 11-16 years old, but is variable depending on environmental factors.  Outside of specific diseases, puberty will occur between approximately 8 and 18-19 in over 95% of the population, and in 100%  of the population (again, assuming no genetic defect or disease) will have occured by 21 or so.  human death, under the best of circumstances, probably will occur at around 85-90 years.  outside of specific non age related diseases, the range will be around 65-115, which is pretty tight.  The fact that we have *never* observed a mammal that lives forever, the genes that control senescence are likely very tightly connected to genetic programs necessary for survival-so that if an animal is missing the genetic program that controls death, it won't survive embryogenesis to begin with (otherwise, some percentage of mammals would live extremely long-which likely is extraordinarily damaging to the population of that species, and is thus dramatically regulated so it will never occur).\nIt is fairly likely that, within the next 100 years, this genetic control program will be dissected and understood, and then it will be a short time until it will regulatable clinically.  \nDeath is controlled by our genes, which are, in the end, simply biochemical control systems, and which are comprehensible with enough study- Then it becomes a societal decision as to how we should manipulate this.\n*edit* There is interesting observation with telomeres, and about 10 years ago, we thought this might be the hidden secret, but unfortunately, it doesn't appear to be so.  In many immortal, or long-living cells, telomeres play no role, and even in cells in which telomeres are artificially extended, there is still senescence (though it appears to occur somewhat later).  Telomeres are a clock that determines how many times a cell may divide before it enters a "cellular suicide" program, and thus it was thought this was critical to lengthening lifespan-however, most sensescence in mammals does not seem to occur because o
591851
Animals have rights while they are alive.\n\nRocks, once had rights.\n\nIn due time (billions of years probably), they may have rights again.
351846
Living things use, store, and emit energies and other chemical compounds; non-living things don't.  Living organsims burn off 90% of all the energy that it intakes and only 10% turns into other muscle tissue or is stored for further usage.  So if a bird eats ten fish then only abou 1 of those fish's nutrients will make up the bird's mass and be stored the other 9 fish's nutrients will be burned in daily activities.  At least I'm pretty sure that's how it is.
479338
Each of these common names refers to more than one species (sometimes several) and the extant or available data for each one may differ, therefore I suggest you look at this site: \nhttp://www.demogr.mpg.de/cgi-bin/longevityrecords/entry.plx\n\nwhere you can find well-recorded lifespan data for many species.  \nGood luck :-)
781417
The smallest organism found on Earth can be measured using a variety of different methods, and can be defined as the smallest by volume, mass, height, or length. Because there is some dispute over what the definition of life is and what entities qualify as organisms, the actual "smallest organism" may be unclear.
1054322
D. Telomerase\n\nIt has been proposed that telomere shortening is the molecular clock that triggers senescence. In other words, as cells divide and the organism ages, the ends of the chromosomes (telomeres) get shorter. (This is believed to be the reason why Dolly, the cloned lamb died early, because she was her age plus her mother's age, since her telomeres kept getting shorter)\n\nTelomerase is an enzyme that causes the telomeres NOT to be shortened, which is one reason why cancer cells can keep growing and do not "age" like normal cells.\n\na future hint, most enzymes end in "ase"
1144623
yes. a housefly's lifespan is only about one to three days.\n\nThere is a good concept by Stephen King that says something like the most important factor in the Universe is size. Size determines speed and time concept. He illustrated that if we could imagine that our whole universe is an atom in a blade of grass in a world of much more larger scale, a hundred billion years to this universe can just be a fraction of a second to that world. The relationship is the same with our world and the atomic world and the sub-atomic world and so on. \n\nInsects are relatively small, and they have a shorter lifespan too. Time passes relatively much slower in our panorama when in comparison to them from our point of view. But these things often just go unnoticed. Like an atom or an ant on a blade of grass.
1113749
http://www.usoe.k12.ut.us/curr/science/sciber00/7th/classify/living/2.htm
921897
Sperm life is dependant  on many variables.Generally sperm lives about three days,but it the sperm are in good\nquality cervical fluid they can live up to 5 days.Sperm that \nreach the optimal enviroment beyond  the female cervix\nmay live for 5 days.Sperm that stays only in the vaginalive only a few hours and even less if exposed to air\noutside the body.Sperm that carry  genetic info for female offspring swim  slower and live longer than the male  designated  sperm.
355307
It isn't a very good control if your cells die before the experiment is complete.  More info is needed to get a more specific answer.
237364
No offense to the other people who answered, but you've gotten some unintelligent and outright dumb answers.  \n\nFirst, you have to define 'life'.  Merriam-Webster (see www.m-w.com) includes 20 definitions!  Here are the pertinent ones, with more comments below.  \n\n"1 a : the quality that distinguishes a vital and functional being from a dead body b : a principle or force that is considered to underlie the distinctive quality of animate beings -- compare VITALISM 1 c : an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction"\n\n"5 a : the period from birth to death "\n\n"8 : a vital or living being; specifically : PERSON <many lives were lost in the disaster>"\n\nDefinitions 1a and 8 define life one way, while 1c and 5 define life in different ways.  It is all in how one interprets them...\n\nMany biologists, including myself, define the beginning of life as the point in time when an organism is viable.  That means that an organism is able to survive in the external environment without nurturing from the parents.  A conservative estimate for the point of time when a fetus might be viable is at the end of the second trimester.  To err on the side of caution, we can even push this back a month; let us say at 5 months instead of 6.  We can push it back a month to account for future increases in technology.  Carl Sagan strongly agrees with this point of view and describes it much more eloquently than I could possibly explain it his book "Billions and Billions".  \n\nDefinition 5a spells out that life begins at birth and ends at death.  This is straightforward but I doubt few would 100% agree with it. \n\nDefinition 1c is at the seat of the controversy over when life begins.  If someone defines life as “the capacity for metabolism, growth, reaction to stimuli, and reproduction”, no one can make the philosophical or logical argument that life doesn’t begin at fertilization or conception.  At that point, one can only lay out their argument for when they feel life begins.  According to the National Institute of Health (NIH), about 50 percent of all fertilized human embryos are spontaneously aborted.  Figuratively, when an embryo is spontaneously aborted, it has reached the ‘end of its life’ (see other definitions of ‘life’), but it doesn’t mean the embryo was alive.  \n\nIn closing, the definition one ascribes to ‘life’ depends on their moral, social, and religious views.  Despite obvious differences in how people will define life, it is paramount to understand someone’s definition, and I hope this little answer helps just a little.
641923
Most of these answers are incorrect. The telomeric shortening hypothesis is not a good one, because some organisms lack telomerase (the enzyme responsible for lenghtening telomeres) and are immortal (like bacteria - though they have circular genomes, and are therefore not a good example). More likely, aging has to do with Insulin signaling and Homeobox gene regulation. However, the truth is that no one knows why we grow old, or why cells begin to produce less collagen and elastin as we age (the reason for wrinkles and other symptoms of aging like degreased vital capacity in respiration).
683177
If it is a living thing it has to be able to reproduce, otherwise it would go extinct.  Protists can reproduce.