scientifically what keeps us from being immortal, or at least living thousands of years like trees?

Question

and can anyone offer their ideas on how to achieve this...

Answer 1

I'll stay strictly biochemical, and not consider teliology or evolution, since the previous answerer addressed some of this.
Though 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).
It 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.
Death 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.
*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 of an inability of cells to divide, and cells such as neurons do not (except for a very small population) divide at all. It's more likely that telomeres protect the body from cancer and other genetic disorders by removing cells which have divided a lot, and may have collected a large proportion of genetic mutation.

Answer 2

Its called engineered obsolescence. The only thing that living things were meant to do is reproduce. And by reproducing, make the next one better adapted to it's environment. The parent is therefore less evolved than the offspring and must be removed from the genetic equation to continue the improvement cycle. Nature never knew that humans would become self-aware and grow beyond the need for obsolescence at this rate. Our gene's didn't keep up with our bodies and minds so we're stuck with it. But the genetic tag that starts the degeneration has been identified and I suspect that a solution is known. But where the heck are you going to put all the people if no one died for thousands of years.

Answer 3

Since we have linear (as opposed to bacterial circular) DNA, it's impossible for our DNA polymerases to proof-read and copy the entire strand. We have telomeres to correct this problem - they are non-coding repeats at the end of each strand that 'buffer' the coding regions of the genome so that nothing important is misread or cut off. As we age, oxydative stress, toxins, and mutations build up and can eventually break DNA and shorten telomeres. Over time, we may lose critical genetic information. One theory suggests that if the telomere problem could be fixed, the aging process would be significantly slowed. However, there has to be more to it than this, as bacteria don't live forever, either.

Answer 4

its all down to the eternal law of biology: every living thing must meet an end,its greater lifespan for some like trees whreas some are transient like humans!
the biology of senescence bears testimony to this,our body constituents right from something as fundamental as a cell to someting prominent as an organ undergoes degeneration.look at athletes, few in sports like football , tennis etc have a surprisingly shorter lifespan due to accelerated degeneration of muscle mass! That does not mean you should not use your body,it means that it depends on which way you use yr body!
ELIXIR OF LIFE exists only in thick,erudite volumes of roman mythologies,not REAL LIVING! To some extent you can lengthen yr lifespan by engaging in stuff like laughter,a fulfilling relationship,health consciousness,empathy etc..........sorry i dont want to sound like a lecturer but it does add a few extra years!
by the way,immortality is not totally desired.......it has its negative vibes,you have to depend on someone for trivial chores everyday if you are already 90+,just imagine what will happen when you are living...........you will practically be a soul trapped in a hollow body....a body sans its own independant zest n vigour, people only remember you when you die....nobody gives a damn when you keep living,they get bored of you.....who wants that kind of life?thats my question to you!

Answer 5

It's thought that one of the reasons we age is because our telomeres (the end of our chromosomes) get shortened by DNA damage, with each cell division, etc. For some reason, this doesn't happen as quickly in trees (the telomere shortening), which is why they live longer. Some scientists are looking into how we can keep our telomeres from shortening and so live longer.

Answer 6

Every day your body takes damage, your cells die etc. We age because at a certain point your body can't keep up with the repairs it has to do, so it just makes a rushed job of it, which decreases the quality (hence the ageing).

Answer 7

The sun has many things that affect humans negatively that doesn't affect the trees. X-rays, Infrared, and many others harm the human skin, where as they don't harm the trees as effectivly as humans.

Plus, we weren't meant to live that long.

Answer 8

see my answer to this question:

http://answers.yahoo.com/question/index;_ylt=AuufGmh3CYqH8xVW_YkMLx_sy6IX?qid=1006052638805

and no it's unlikely to happen for us, not without some cost in terms of quality of life, reproductive ability, etc.