# Accelerated natural selection as a result of war? **URL:** \ **Category:** Factual Questions\ **Created:** [December 20, 2019, 4:14pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145 "2019-12-20T16:14:49Z")\ **Posts on this page:** 9\ **Page:** 3
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [December 23, 2019, 5:46pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/41 "2019-12-23T17:46:10Z")
> [@Colibri](#): > > I am not away of distinct selection pressures created by forests. You were referring exclusively to humans here, right? [I half-composed a long rant about how that’s even more clueless than a tree expects from a bird, regarding shade tolerance, changed food sources, etc. etc. But then I realized you probably meant humans only.] ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [December 23, 2019, 5:59pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/42 "2019-12-23T17:59:51Z")
The other problem with using war as selection is that in the Good Old Days™ quite often people would be married and pop out a few kids before they went off to war, so not very great selective breeding pressure. Plus, who got killed in war was relatively arbitrary - you may be a great fighter, but three guys with spears or bows can still take you down from a safe distance. The knights of Crecy and Agincourt were taken out by footmen with bows. OTOH, the Maori of NZ were fighters using big clubs before the Europeans arrived, so presumably this should have selected for the bigger and stronger. One other effect of war that might be interesting - there’s the story that 1 in 200 of men across Eurasia are descendants of Genghis Khan. How would that happen? ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [December 23, 2019, 7:26pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/43 "2019-12-23T19:26:53Z")
> [@Wesley\_Clark](#): > > How would war change a group of people? You’d have to have some kind of inheritable characteristic that would confer some kind of advantage- survival and/or reproductive, which warfare would select for. From what I’ve read, in the hunter-gatherer era, low-level warfare was pretty much endemic, so there would be a lot of opportunities for traits to be selected for via evolution. AFAIK (not a evolutionary science guy), those traits could be anything from different head bone structures to different blood clotting, to resistance to infection, or something less tangible, like faster reflexes, better strength, or more smarts, leading him to be a more successful warrior, and therefore higher status, giving him more reproductive opportunities. But in the modern day , warfare IMO is too lethal, too random, and too episodic to really have any significant traits being selected for. I’d even go so far as to say that 20th century war probably would turn out to be selecting for otherwise maladaptive traits- weakness, etc… that would prevent a soldier from volunteering or being chosen to be a soldier, as the very healthy, intelligent ones are off getting shot, while the ones with bone spurs, clubfeet, bad vision, etc.. are home not getting shot. ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [December 23, 2019, 9:13pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/44 "2019-12-23T21:13:34Z")
> [@bump](#): > > You’d have to have some kind of inheritable characteristic that would confer some kind of advantage- survival and/or reproductive, which warfare would select for. > > From what I’ve read, in the hunter-gatherer era, low-level warfare was pretty much endemic, so there would be a lot of opportunities for traits to be selected for via evolution. AFAIK (not a evolutionary science guy), those traits could be anything from different head bone structures to different blood clotting, to resistance to infection, or something less tangible, like faster reflexes, better strength, or more smarts, leading him to be a more successful warrior, and therefore higher status, giving him more reproductive opportunities. How about left-handedness? Left-handed fighters have been shown to be more successful - left vs right is constant for the left-handed, and much rarer for the right-handed. There is a significantly higher proportion of left-handed sportspersons in high-level sports where this makes a difference. So if there is a selective pressure (primarily hand-to-hand combat up to the late middle ages) we would expect to see a higher rate of left-handedness due to evolution. However, the evidence suggests that the rate of left-handedness in the human population has remained relatively constant (at about 10%) since the times of the Neanderthal. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [December 23, 2019, 9:28pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/45 "2019-12-23T21:28:53Z")
Handedness happens all throughout the animal kingdom–in mollusc shells, for example. ---
**Author:** ![RioRico](https://avatars.discourse-cdn.com/v4/letter/r/f04885/32.png) [@RioRico](https://boards.straightdope.com/u/RioRico)\ **Post date:** [December 23, 2019, 9:38pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/46 "2019-12-23T21:38:51Z")
The obvious genetic change results when conquerors slaughter or enslave vanquished men and rape their women. Then, depending on the numbers of conquerors and vanquished, victors may be absorbed into the local population. ---
**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:** [December 23, 2019, 9:50pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/47 "2019-12-23T21:50:15Z")
> [@Colibri](#): > > When European and African diseases largely decimated Native American populations in the Americas after Columbus’s voyage, agricultural areas in many places soon reverted to forest. But that was more the result of disease rather than war, and I am not away of distinct selection pressures created by forests. > [@Quercus](#): > > You were referring exclusively to humans here, right? > [I half-composed a long rant about how that’s even more clueless than a tree expects from a bird, regarding shade tolerance, changed food sources, etc. etc. But then I realized you probably meant humans only.] I think the context of my remark makes it clear I was talking about humans. It has been postulated that the short stature of African pygmies could be an adaptation to living in dense rainforests, but there are other short populations that live in open environments. ---
**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:** [December 23, 2019, 9:55pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/48 "2019-12-23T21:55:16Z")
> [@RioRico](#): > > The obvious genetic change results when conquerors slaughter or enslave vanquished men and rape their women. Then, depending on the numbers of conquerors and vanquished, victors may be absorbed into the local population. Conquest (as opposed to war by itself) does have an effect on the genetic makeup of populations. In Panama, 70% of the population has mitochondrial DNA (inherited exclusively through the female line) of indigenous origin, while 70% of men have Y-chromosomes (inherited only through the male line) of European origin. This reflects the fact that the Spanish conquerors came as single men without families, and took (often many) partners from the indigenous population. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [December 24, 2019, 6:48pm UTC](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145/49 "2019-12-24T18:48:10Z")
Maybe there have been examples of invasive species introduced to help the war effort that had long term effects? [Previous page](https://boards.straightdope.com/t/accelerated-natural-selection-as-a-result-of-war/845145.md?page=2)