why human being cannot live more than 100 years. usually we die at 80 or 90 year old.?

Question

if you believe in god. in the bible it said, Adam died at around 948 year old and Eve at around 936 year old.

Answer 1

Cell error in the replication leaves us with a time limit for our life and there are even certain parts of the DNA strand that make sure cells age and eventually die.

When cells create an error in reproduction several things can happen; the cell dies, the cell is poor and will later be replaced; or cancer. Cancer is cells with errors on extreme overdrive. They push out the good cells, creating a malignant growth; a tumor. This tumor can become life threatening, if the cancer cells start to leave it then they can spread through the body inciting more cells to go cancerous.

Our cells DNA have a limit to how often they can divide and reproduce themselves.

According to Wikipedia: http://en.wikipedia.org/wiki/DNA_repair
“Senescence, an irreversible state in which the cell no longer divides (mitosis), is a protective response to the shortening of the chromosome ends (telomeres). The telomeres are long regions of repetitive noncoding DNA that cap chromosomes and undergo partial degradation each time a cell undergoes division (see Hayflick limit.”

These telomeres put a limit on a cell’s life. When the telomere is reached the cell can no longer reproduce and so it dies. Lose enough of them and the organism dies.

Scientists are currently working on a way to remove or change those telomeres so they can lengthen the human lifespan. Otherwise we are limited to 60 years before cumulative damage starts to cause problems. We can medically extend the lifespan beyond 60 years, but at a cost with things like arthritis, organ failure, loss of sight and other complications that we know as aging. The problem is that the organs can be replaced, the skin tightened, even hip joints can be replaced with arthritis destroys them, but we can’t do much to repair or rejuvenate the brain. So while the best medical care can get you beyond 150, you will probably be in a wheel chair unable to walk and you will lose some sensation and feeling in your body due to nerve damage.

Alzheimer's may be just such a problem coming out. Usually it only appears in people who are far beyond the age of 40. After that point evolution is finished with us, females lose their ability to reproduce and any changes made in the body after that point will not be carried on to future generations. So as far as evolution is concerned you can drop dead at age 40. When mankind started to change their environment to suit themselves they stopped evolving. The English language has changed more than the human race has since Homo Sapiens first started walking around. The biggest changes are less hair, taller height, and (thanks mostly to technology) an increased lifespan. Entire species have evolved and changed in a few generations, yet modern man is pretty similar to say an ancient Egyptian.

Answer 2

Dan S give a very complete answer, I don't think I can do anything to make it better. This is how I understand it. When you are a baby when your skin shed, your hair fall off, your nail break, the replacement part...like thenew hair that grow out to replace the one that fall off is a 100% replica of each other. But as we grow older we breathe in polute air, we eat the wrong kind of food so we are malnourish although we are overweight, we don't exercise, our posture are incorrect due to bad habits, we consume poison like alcohol and tobacco among other things, so the new hair, nail, cells....that come out is only a fraction of the original parts....eventually it became 0, that's when you cease to exist. I believe if you live in a bubble ( a medical control environment ), you can live much longer than 100 but what's life if you have no where to go.....

Answer 3

What??
I know personally of several people who have lived to be 102,103, and 104. Friends I shoot pool with and play cards with are in their eighties. So I miss your point.