# I have figured out why we are mortal **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 26, 2017, 1:30pm UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306 "2017-12-26T13:30:11Z")\ **Posts on this page:** 6\ **Page:** 3
**Author:** ![Turek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/turek/32/18782_2.png) [@Turek](https://boards.straightdope.com/u/Turek)\ **Post date:** [December 27, 2017, 7:30pm UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/41 "2017-12-27T19:30:10Z")
Being immortal means you never have to take Philosophy in JuCo. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [December 27, 2017, 8:25pm UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/42 "2017-12-27T20:25:19Z")
> [@Wesley\_Clark](#): > > Do people know why we age though? > > I was under the impression that we age because there is no evolutionary pressure to keep us alive after reproductive age. So there is natural selection pressure to keep us alive long enough to birth and raise a new generation, after that evolution doesn’t care. So no selection pressure to make people live forever. Just pressure to live long enough to have kids that survive to reproductive age, after that your body falls to the powers of entropy. > > Also supposedly some traits that are helpful when you are young are harmful when old. I don’t have examples, but I’ve heard some aspects of heart disease or dementia are due to traits that are helpful when you are young. > > But anyway, we die because evolution has no incentive to keep us alive after we’ve procreated and our children have reached independence and maturity. > > Supposedly thats a big part of it. Then again, turtles don’t care for their young and turtles can live hundreds of years. Who knows. Evolutionarily speaking there is a bit of pressure to live a bit past childbearing age, as our children require more training and assistance than any other animal child. Having parents and even grandparents stick around a bit longer helps grow our communities and gives a greater chance for knowledge and skills to be passed down. But yeah, we age because, almost by definition, there really can be no evolutionary pressure to become immortal. ---
**Author:** ![Go\_Arachnid\_Laser\_1](https://avatars.discourse-cdn.com/v4/letter/g/b2d939/32.png) [@Go\_Arachnid\_Laser\_1](https://boards.straightdope.com/u/Go_Arachnid_Laser_1)\ **Post date:** [December 27, 2017, 8:50pm UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/43 "2017-12-27T20:50:25Z")
Does that mean that sociopaths live forever? ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [December 28, 2017, 1:34am UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/44 "2017-12-28T01:34:53Z")
This is why people shouldn’t try to adjust their meds without consulting their doctor. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [December 28, 2017, 2:24am UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/45 "2017-12-28T02:24:46Z")
> [@k9bfriender](#): > > Evolutionarily speaking there is a bit of pressure to live a bit past childbearing age, as our children require more training and assistance than any other animal child. Having parents and even grandparents stick around a bit longer helps grow our communities and gives a greater chance for knowledge and skills to be passed down. > > But yeah, we age because, almost by definition, there really can be no evolutionary pressure to become immortal. There is evolutionary pressure to live longer. If Ann’s children have a freak mutation that they never age, then they are not only likely to survive much longer than Bob’s, ordinary, children, but her children can keep squirting out kids of their own indefinitely. How species arrive at their finite lifespan is not only a function of how long their infancy is, it’s also partly a function of what their life expectancy assuming a healthy body is. Basically if the niche your species exploits means that few would make it to 10 years old, even without ageing, then genes whose effects are not detrimental until year 10 are not selected out of the genepool (and may even be selected _for_ if they have positive effects prior to that kind of age). ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [December 28, 2017, 2:31am UTC](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306/46 "2017-12-28T02:31:14Z")
I’m a bit uncomfortable with the way this thread started as metaphysics, but then we’re now talking about real species and why they aren’t immortal. Immortality in the sense of the OP, where we can’t die, is not something that could happen in our universe. Living indefinitely however, \*is \*something physically possible. And indeed there are a few species that display what we call negligible senescence. [Previous page](https://boards.straightdope.com/t/i-have-figured-out-why-we-are-mortal/805306.md?page=2)