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rhia
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If cells can always reproduce and replace themselves then why do living beings die?
Noticibly F.A.T said:So, aychamo, are you saying that essentially, the meaning of life is to reproduce?
aychamo said:I think there is a very simple answer to that. Nothing would be selecting for or against the person living to whatever age, because they have already reproduced. Once a person has had their kids, it doesn't matter if they live another day or a thousand more years.
selfAdjoint said:Death and sex are two definite evolutionary strategies to speed up evolution, perhaps to keep up with the speed of virus evolution. They go back to the dawn of the metazoan lifeforms a billion years ago. Sex mixes and matches genes into new combinations. And death gets old combinations off the stage to allow the new ones to flourish.
marcus said:Does anybody know when it was that Evolution invented death?
Some species had to accidentally acquire an internal natural death clock and then that species would have experienced an evolutionary advantage over species that hadnt learned the trick of dying
It would only be an advantage if the species had already invented sex.
or some other method of scrambling..
So when did sexual reproduction evolve? Anybody have a guess?
Phobos said:Of course, a good question to what aychamo and I just said would be "why can't humans remain fertile their entire lives and therefore there would be a selection process favoring longer/eternal life?" I'll have to get back to that question (I recall Dawkins addressing that one) but perhaps it relates to the cost-benefit of self-maintenance vs. reproduction.
Janitor said:My own idea is that there are some catastrophes that can overwhelm and kill any individual of a species so easily that evolution just never had the chance or reason to select for genes that would endow an individual with ultra-long life genes. I will give a simple model to show what I am thinking:
Janitor said:... evolution just never had the chance or reason to select for genes that would endow an individual with ultra-long life genes..
Marcus said:Death doesn't make sense for something that is only one cell and reproduces by symmetrical cell-division. It should not age, and i do not think that Amoebas do age. the cell has to go to extra trouble to age.
Chronos said:The Hayflick limit is an appealing explanation
http://www.infoaging.org/feat4.html
Phobos said:Men do not go through menopause perhaps because their fertility does not decrease that much with age and they invest less (physically) in bearing children than women do.
Janitor said:My own idea is that there are some catastrophes that can overwhelm and kill any individual of a species so easily that evolution just never had the chance or reason to select for genes that would endow an individual with ultra-long life genes. I will give a simple model to show what I am thinking:
marcus said:I think you may have it backwards.
It takes extra trouble to make a cell that will age and die of its own accord.
This had to evolve.
Early cells apparently did not have this feature.
The original plan for singlecell life did not involve dying. Dying had to be
"invented" by evolution, as an "added wrinkle", because from the selfish gene standpoint it is an improvement.
If they didnt then they would fill up all the niche room and there would be no place to put the babies. So the genes wouldn't be able to try new combinations and evolution would grind to a halt. Some catastrophic thing like a new disease would probably get 'm
I believe that the answers in this thread were more related with lifespan, aging, than with the fact of death. With independence of apoptosis at cellular level, death of complex organism seems to be due in most cases to mistakes (somatic mutations) or to lesions induced by environment (infectious agents, chemical, physical traumas...)rhia said:If cells can always reproduce and replace themselves then why do living beings die?
sciart said:The Second Law of Thermodynamics
Living beings die because of the natural cycle of life. All living organisms, including humans, have a limited lifespan and eventually reach a point where their bodies can no longer sustain life.
There is no specific age at which all living beings die. The lifespan of different organisms varies greatly depending on factors such as genetics, environment, and lifestyle.
While death is a natural part of life, there are ways to delay it or prevent it from occurring prematurely. Eating a healthy diet, exercising regularly, and avoiding harmful substances can help extend lifespan.
No, different living beings experience death in different ways. Some organisms, such as plants, may not experience death in the same sense as animals do. Additionally, the experience of death may vary among different species of animals.
After death, the body undergoes a process called decomposition, where it is broken down by bacteria and other organisms. This process returns nutrients to the environment and allows new life to grow.