# Natural human lifespan in the wild, without modern medicine **URL:** \ **Category:** Factual Questions\ **Created:** [July 12, 2013, 9:17pm UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358 "2013-07-12T21:17:52Z")\ **Posts on this page:** 11\ **Page:** 3
**Author:** ![Mr.Bill](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mr.Bill](https://boards.straightdope.com/u/Mr.Bill)\ **Post date:** [February 3, 2014, 4:36pm UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/41 "2014-02-03T16:36:58Z")
> [@mattdillon87](#): > > The concept of being genetically programmed to live until one is useless to a tribe is a hypothesis. I believe this is the grandmother hypothesis. But the fact is, a fertile state is a person’s ideal state. Because none of us would be here if people weren’t meant to be fertile. And ideally, the end of our lifespan should be when fertility is no longer possible. So, a woman gives birth to a child between around age 14-21, and dies at 40. You have to think about it from the stance of what is best for the long-term survival of the whole genetic line. From that standpoint, it makes no sense for individuals to live forever. They need to die to make room for new individuals who will have a different (and possibly better) selection of genes. This might mean new mutations that turn out to be advantageous or it might simply mean a better combinaton of existing genes. If there is no room for new individuals with new genetic makeups, then the long-term ability of the population to adapt to changes in the environment is decreased. But, from the same standpoint, a lifespan that is long enough to provide for cultural continuity is also advantageous to the population. At least for creatures that have culture. Bacteria probably don’t fit into this idea. So you have two competing forces, one requiring death, the other favoring a long life span. Add in the idea of limited resources keeping populations at or below a certain size. These forces, through the process of natural selection tend toward the equilibrium which is of maximum benefit to the genetic line. The point of equilibrium may vary according to shifts in these forces, but it is always present. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 3, 2014, 5:00pm UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/42 "2014-02-03T17:00:02Z")
> [@Mr.Bill](#): > > From that standpoint, it makes no sense for individuals to live forever. They need to die to make room for new individuals who will have a different (and possibly better) selection of genes. This might mean new mutations that turn out to be advantageous or it might simply mean a better combinaton of existing genes. This reasoning depends on selection at the population level, rather than the individual. While this is possible, it is not necessary to invoke population selection to understand why individuals don’t live forever. Within any population, there will be a certain amount of attrition due to reasons that have nothing to do with aging. Individuals will die due to accident, disease, predation, etc. For this reason, each older age class will be smaller than the one before it, and even if individuals reproduce they will contribute less genetically to the population as a whole. By the time you get to very old individuals, they are so few that they are contributing very little genetically to the overall population. Selection against genes that promote long life span will thus be comparatively weak. ---
**Author:** ![mattdillon87](https://avatars.discourse-cdn.com/v4/letter/m/58956e/32.png) [@mattdillon87](https://boards.straightdope.com/u/mattdillon87)\ **Post date:** [February 4, 2014, 1:07am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/43 "2014-02-04T01:07:35Z")
> [@Mr.Bill](#): > > You have to think about it from the stance of what is best for the long-term survival of the whole genetic line. > > From that standpoint, it makes no sense for individuals to live forever. They need to die to make room for new individuals who will have a different (and possibly better) selection of genes. This might mean new mutations that turn out to be advantageous or it might simply mean a better combinaton of existing genes. > > If there is no room for new individuals with new genetic makeups, then the long-term ability of the population to adapt to changes in the environment is decreased. But, from the same standpoint, a lifespan that is long enough to provide for cultural continuity is also advantageous to the population. At least for creatures that have culture. Bacteria probably don’t fit into this idea. > > So you have two competing forces, one requiring death, the other favoring a long life span. Add in the idea of limited resources keeping populations at or below a certain size. These forces, through the process of natural selection tend toward the equilibrium which is of maximum benefit to the genetic line. The point of equilibrium may vary according to shifts in these forces, but it is always present. Sorry, but I have to disagree with you over the existence of genes. I’m a creationist. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 4, 2014, 1:16am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/44 "2014-02-04T01:16:50Z")
> [@mattdillon87](#): > > Sorry, but I have to disagree with you over the existence of genes. I’m a creationist. **Moderator Note** **mattdillon87** , General Questions is for obtaining factual answers to questions. If you want to make arguments from a non-scientific perspective, then take it to Great Debates. The existence of genes is a well-established fact that is not disputed even by most creationists. Colibri General Questions Moderator ---
**Author:** ![mattdillon87](https://avatars.discourse-cdn.com/v4/letter/m/58956e/32.png) [@mattdillon87](https://boards.straightdope.com/u/mattdillon87)\ **Post date:** [February 4, 2014, 1:27am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/45 "2014-02-04T01:27:57Z")
> [@Colibri](#): > > You can’t draw evolutionary conclusions from a fabricated “ideal situation,” especially with one that is so far from the realities of human social behavior. Few primitive human cultures practiced pure monogamy. A degree of polygyny is common, where older and more successful males who control more resources can take younger, fertile wives. Even in cultures where polygyny is not practiced, older males often take younger wives. Add to this the fact that a significant number of births will be the result of unfaithfulness by partners. Your postulated conditions will not be typical. I’m not saying my “postulated conditions” are typical (I said they were ideal). But they should be. I’m not trying to draw evolutionary conclusions. I don’t believe in evolution. The thing is, none of us, not you or I, know if evolution is true. Nobody can possibly know how humans originated, because none of us were there. Unless someone built a time machine. ---
**Author:** ![mattdillon87](https://avatars.discourse-cdn.com/v4/letter/m/58956e/32.png) [@mattdillon87](https://boards.straightdope.com/u/mattdillon87)\ **Post date:** [February 4, 2014, 1:41am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/46 "2014-02-04T01:41:59Z")
> [@Colibri](#): > > **Moderator Note** > > **mattdillon87** , General Questions is for obtaining factual answers to questions. If you want to make arguments from a non-scientific perspective, then take it to Great Debates. The existence of genes is a well-established fact that is not disputed even by most creationists. > > Colibri > General Questions Moderator I wouldn’t say fact, but a theory. However, you are right, in that this is not the thread for this type of subject. ---
**Author:** ![mattdillon87](https://avatars.discourse-cdn.com/v4/letter/m/58956e/32.png) [@mattdillon87](https://boards.straightdope.com/u/mattdillon87)\ **Post date:** [February 4, 2014, 1:52am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/47 "2014-02-04T01:52:24Z")
> [@MandaJo](#): > > But what about the children she gives birth to between 35-40? Is it really “fertility” if a chunk of your offspring die because you were not there to protect and provide for them? The way I look at it is this: the time she should give birth is the time she becomes fertile. So she should give birth in her mid teens to early twenties, prior to the 35-40 age range you mentioned. Well, at least, that’s the way it should be. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 4, 2014, 2:00am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/48 "2014-02-04T02:00:42Z")
> [@mattdillon87](#): > > I’m not saying my “postulated conditions” are typical (I said they were ideal). But they should be. I’m not trying to draw evolutionary conclusions. I don’t believe in evolution. The thing is, none of us, not you or I, know if evolution is true. Nobody can possibly know how humans originated, because none of us were there. Unless someone built a time machine. > [@mattdillon87](#): > > I wouldn’t say fact, but a theory. However, you are right, in that this is not the thread for this type of subject. > [@mattdillon87](#): > > The way I look at it is this: the time she should give birth is the time she becomes fertile. So she should give birth in her mid teens to early twenties, prior to the 35-40 age range you mentioned. Well, at least, that’s the way it should be. **Moderator Instructions** **mattdillon87** , this forum is not for discussing what “should be.” I’m instructing you to stop posting in this thread, and start a new thread in Great Debates if you wish to pursue this argument any further. Additional posts by you in this thread may be subject to a warning. Colibri General Questions Moderator ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 4, 2014, 3:29am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/49 "2014-02-04T03:29:09Z")
> [@nevadaexile](#): > > Four of the five men you mentioned were never in combat. George Washington saw combat in two separate wars and had to spend a great deal of time worrying about his personal survival which had to take its toll upon his health. Also, Washington is thought to have been killed by the doctors, [who bled him to death.](https://en.wikipedia.org/wiki/George_Washington) ---
**Author:** ![buddha\_david](https://avatars.discourse-cdn.com/v4/letter/b/ee7513/32.png) [@buddha\_david](https://boards.straightdope.com/u/buddha_david)\ **Post date:** [February 4, 2014, 3:49am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/50 "2014-02-04T03:49:29Z")
> [@mattdillon87](#): > > Sorry, but I have to disagree with you over the existence of genes. I’m a creationist. Simply curious…do you believe gravity doesn’t exist, either? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 4, 2014, 4:01am UTC](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358/51 "2014-02-04T04:01:48Z")
> [@buddha\_david](#): > > Simply curious…do you believe gravity doesn’t exist, either? [Moderating] Let’s drop this discussion as a sidetrack. Open a thread in IMHO or GD if you want to query **mattdillon37** about his beliefs. Colibri General Questions Moderator [Previous page](https://boards.straightdope.com/t/natural-human-lifespan-in-the-wild-without-modern-medicine/663358.md?page=2)