Why people die even all part of body in good condition?!
Question: In mitosis, the genetic material is not completely reproduced -- a bit of DNA is lost at the end of a chromosome at each reproduction. There is some excess DNA available, so you can reproduce through forty generations or so before losing the good stuff. But eventually the good stuff starts getting lost, and cells start to die, so no one can live much over 120 years. Long life is not required for reproductive success, so evolution does not favor immortality, which would have costs. Look up "telomerase" for more details.
Answers: In mitosis, the genetic material is not completely reproduced -- a bit of DNA is lost at the end of a chromosome at each reproduction. There is some excess DNA available, so you can reproduce through forty generations or so before losing the good stuff. But eventually the good stuff starts getting lost, and cells start to die, so no one can live much over 120 years. Long life is not required for reproductive success, so evolution does not favor immortality, which would have costs. Look up "telomerase" for more details.
thats the way it is...