7 ms·

Investigating the case of human nose shape and climate adaptation (2017)

139 points by thunderbong 2y ago

al__be__rt 2y ago
[flagged]
ebina-chonk 2y ago
[dead]
baxtr 2y ago
From the author summary: > We find that variation in both nares width and alar base width appear to have experienced accelerated divergence across human populations. We also find that the geospatial distribution of nares width is correlated with temperature, and absolute humidity, but not with relative humidity. Our results support the claim that local adaptation to climate may have had a role in the evolution of nose shape differences across human populations. I really wonder how nose shape can affect evolution. What is the mechanism? How can better air lead to higher numbers of successful offspring or fatalities?
- kseistrup 2y ago
  The parameters affect the temperature and humidity of the air that reaches the lungs. E.g., a long slender nose could perhaps moisten and warm up dry frosty air better than a shorter wider nose.
  - 0xEF 2y ago
    Speaking as someone with a long slender nose, I have my doubts about it moistening dry frosty air. During the Winters, the only thing my nose seems to be good for is producing blood and dried mucus wafers like some cursed Triscuit factory.
    - croisillon 2y ago
      Yay free proteins!
    - kseistrup 2y ago
      It's not about your nose. It's about the relative differences of the air reaching the lungs when inhaled through different nose. You may not think that your nose does a very good job (or perhaps I picked a wrong example), but perhaps the job would get done much worse by a short wider nose. Some environmental parameters are temperature and absolute humidity. But there are also significant differences in sex when a other parameters are equal. So perhaps the correlation is not so straight forward.
      - ChrisMarshallNY 2y ago
        Andean Indians are known for fairly wide, prominent noses. They also have massive thoraxes and lung capacity.
      - 0xEF 2y ago
        I can see that. Contrary to my personal feelings about my own nose, having grown up in a more Northern latitude where Winters were much, much harsher than what I experience now, there was a few key things I learned at an early age that stuck with me well into adulthood. Breathing through your nose in the cold while walking to class was one of them. I heard this a lot back then, the logic being as you propose; that it just gives the cold air a bit more time to warm before it reaches your core. Adding to that, you were also supposed to breathe slowly, rather than taking fast, gulping breathes. That just added to the reasons to avoid over-exerting yourself in the cold, which poses other risks. Other stuff had more to do with choice of clothing material, layering, etc, but that's not really applicable to this conversation. Interestingly, while it still does get cold where I live now, nobody really pays attention to these rules. I'd say the difference between the two areas is something like -5F on average, give or take. I am not sure how significant that is.
        lproven 2y ago
        > Breathing through your nose in the cold while walking to class was one of them. After extensive nasal surgery in 2009 this became an option for me again, after over 20 years when it wasn't. I discovered a less-discussed rider: yes, it seems gentler on the lungs to breathe in through your nose in sub-zero weather, but there is a condition: you should breathe out through your nose as well. Exhaling warms the structures in the nose so it can warm the next inhalation. But, for me, that same sub-zero weather often causes my nose to make more mucus -- so breathing both in and out means a lot more use of a handkerchief, or a nasty snotty moustache. It's sometimes simply not worth it. :-/
- cyrillite 2y ago
  Respiratory efficiency is a pillar of health and performance, from sleep to hunting and fighting. I wouldn’t be surprised to find that marginal gains make a big difference and can be passed on.
- lm28469 2y ago
  > How can better air lead to higher numbers of successful offspring or fatalities? Try running XX hours after an antelope and report back, most animals aren't optimised for long distance, humans are, you can hunt most things by following them and waiting for them to collapse, surely having better air intake helps. It might be something as dumb as more antelope meat = more social points = you get to bang more. Why do 70%+ of the world population has brown eyes ? It offer marginal UV resistance but nobody becomes blind or sterile because they have blue eyes, certainly not before they can reproduce. Chances of reproduction can also be dictated by other things like attractiveness, and these are also very dependant on cultures and time periods.
  - DiscourseFan 2y ago
    Its more like if your tribe has access to more meat they can produce more offspring. I wouldn't think of this in terms of individual prowess.
    - BurningFrog 2y ago
      Pretty sure the best hunter gets the most kids on average.
      - DiscourseFan 2y ago
        Source?
        BurningFrog 2y ago
        Just common sense. The guy who brings home the most food will have the most surviving children. He will also be very attractive to women.
        DiscourseFan 2y ago
        It was also "common sense" not so long ago that the earth was the center of the universe. You're engaging with me disingenuously.
- DrScientist 2y ago
  Nose filters, and adjusts air temperature and humidity - it's not just a passive in/out hole. Evaporation is a big factor in both controlling temperature and water retention/loss ( that's why dogs pant in hot weather ). Remember the surface of your lungs are topologically on the outside - they are large and wet and are sensitive to both physical dust etc as well as potential infection. The nose design has to find the best balance across all these factors ( as well as being important in the sense of smell ).
- wiether 2y ago
  Silly suggestions related to snoring: - harder to find mating partner before earplugs were inventend - easier for your enemies/predators to catch you in your sleep
- SamBam 2y ago
  The article mentions an increase in upper respiratory tract infections in the air being breathed in is not humid enough. The hypothesis seems to be that in drier climates, humans need longer noses to increase the humidity of the air to an optimal level.
justlikereddit 2y ago
[flagged]
- nothrowaways 2y ago
  This is how our understanding about the world moves forward.
onetokeoverthe 2y ago
[flagged]
temptemptemp111 2y ago
[dead]
nomoreusernames 2y ago
[dead]
metalman 2y ago
There are a large amount of enviromental adaptations in many human populations, a lot of them to do with enzimatic adaptations. Climate as a term in this context is only usefull if you include, everything, diet, the ability to pass certain contaminents, such as high arsinic concentrations in water, vs binding say calcium. The full list, is, well, everything!, horribly complex, the nose ,perhaps working as a proxy indicator for a number of less visible adaptations, as succes in more extream environments is absolutly dependent on multiple adaptations, none of which is optional over generational time spans, as extream conditions, in an already extream environment, are going to eliminate marginal indivduals.
microtherion 2y ago
Weirdly, I saw this paper mentioned just this morning, in the context of an r/AskHistorians post discounting the possibility of an African origin for Olmecs. Sounded interesting, and then I saw it linked here.
- dagenleg 2y ago
  Same. Feels like we exist in a very small bubble doesn't it?
abricq 2y ago
On a slightly related topic, I remember to have seen an exposition where an artist was asked to represents what a human who has naturally evolved to survive a car crash might look like. And it has a cool / terrifying website: http://www.meetgraham.com.au/view-graham http://www.meetgraham.com.au/view-graham Quite fascinating topic to wonder about: how long will it take for the modern era to genetically change us ?
- highcountess 2y ago
  To answer your question, it already has changed us in many ways. You are not the only one who does not realize this though. It is in fact the prevailing position. We have diseases and genetic defects, among other impacts through modern behaviors and environments/toxins, which are also retained in the genetic mutational load. We even have a whole lot of energy and human activity working to counter evolutionary pressures and assure those accumulated mutational loads remain in the genetic code.
  - amanaplanacanal 2y ago
    Fitness depends on the specific environment the creature is in. Environmental fitness for the ancestral environment when all humans were hunter-gatherers is not necessarily the same as fitness for living in an industrial society. Evolutionary pressure still works just fine.
- spacebanana7 2y ago
  Humans are beyond evolution. There's no meaningful selection pressure in our environment that kills people before reproductive age, so there's no reward for adaptations.
  - mattigames 2y ago
    I have always considered that a bug, not a feature.
  - svara 2y ago
    Totally wrong, killing humans is not required for evolution. Ignoring genetic drift and taking into account only natural selection, all that's needed is differences in fitness, i.e. differences in how much an individual contributes to the gene pool of future generations.
tpierce89 2y ago
I would like to see if there is a correlation between Sleep Apnea cases and nose shape to determine if there is a link between humans living in an area they are not adapted to and how that affects their ability to breathe normally.
- ninetyninenine 2y ago
  Sleep apnea usually comes from the back of the throat. It’s not a nose thing as much.
- woolion 2y ago
  I suspect the impact would be extremely small compared to BMI, so it would be likely that there would be a link because of some dependent variables.
  - oremolten 2y ago
    I bet there is also a large correlation with computer/phone neck and posture
  - hammock 2y ago
    Ok, what about looking at nose shape of diaspora that have historically (multigenerationally) high BMI? Not an expert but might suggest Inuit, some Pacific Islanders, Māori, west Africans maybe. How are their noses shaped and anything that might help with apnea?
  - ratmeadow 2y ago
    BMI is a contributing factor, but so is neck and throat anatomy, regardless of weight. There are plenty of non-overweight people who have sleep apnea. And treatment sucks because so many doctors don't know anything past "you should lose weight".
- BurningFrog 2y ago
  People probably sleep in very similar conditions in all climates.
davidw 2y ago
Going to use this as a comeback next time my wife makes a comment: "I'm just well-adapted to certain climates, so there!"
boxed 2y ago
West African, but not East African? That seems like an enormous problem in itself.
nickdothutton 2y ago
Also there is a relatively new (5800 years ago) mutation somehow related to brain development, the ASPM gene. The mutation is somehow advantageous to the individual, but we don't yet know exactly why/how. https://en.wikipedia.org/wiki/ASPM_(gene)#Evolution https://en.wikipedia.org/wiki/ASPM_(gene)#Evolution
InfiniteLoup 2y ago
There is a rather distinct type of nose which I've only ever observed with people of Ukrainian ethnic descent. Now I wonder if that is in fact some type of adaptation to local climate because the people of the surrounding areas don't seem to have that nose shape to the same extent.
SamBam 2y ago
If I'm reading this right, the hypothesis seems to be that in drier climates, humans need longer noses (simplifying) to increase the humidity of the air to an optimal level. Did the authors propose a counter-evolutionary pressure, to favor a shorter nose in more humid environments? It's possible that the mechanism would be as simple as "it requires more resources to maintain a longer nose," but I'm also wondering if they suggested anything.
indulona 2y ago
[flagged]
Sam6late 2y ago
On a slightly related issue, I noticed that my nose gets bigger,in my photos, it turned out it was mostly irritation swelling due to pollution, while in a Nordic country with cleaner air quality, I noticed that is back to normal. And now I am always checking iqair.com- and it says:"PM2.5 concentration is currently 3.6 times the World Health Organization annual PM2.5 guideline value.
idunnoman1222 2y ago
Do people with bigger noses have fewer upper respiratory tract infections or no?

139 points by thunderbong 2y ago

al__be__rt 2y ago

[flagged]

ebina-chonk 2y ago

[dead]

baxtr 2y ago

From the author summary: > We find that variation in both nares width and alar base width appear to have experienced accelerated divergence across human populations. We also find that the geospatial distribution of nares width is correlated with temperature, and absolute humidity, but not with relative humidity. Our results support the claim that local adaptation to climate may have had a role in the evolution of nose shape differences across human populations. I really wonder how nose shape can affect evolution. What is the mechanism? How can better air lead to higher numbers of successful offspring or fatalities?

kseistrup 2y ago
The parameters affect the temperature and humidity of the air that reaches the lungs. E.g., a long slender nose could perhaps moisten and warm up dry frosty air better than a shorter wider nose.
- 0xEF 2y ago
  Speaking as someone with a long slender nose, I have my doubts about it moistening dry frosty air. During the Winters, the only thing my nose seems to be good for is producing blood and dried mucus wafers like some cursed Triscuit factory.
  - croisillon 2y ago
    Yay free proteins!
  - kseistrup 2y ago
    It's not about your nose. It's about the relative differences of the air reaching the lungs when inhaled through different nose. You may not think that your nose does a very good job (or perhaps I picked a wrong example), but perhaps the job would get done much worse by a short wider nose. Some environmental parameters are temperature and absolute humidity. But there are also significant differences in sex when a other parameters are equal. So perhaps the correlation is not so straight forward.
    - ChrisMarshallNY 2y ago
      Andean Indians are known for fairly wide, prominent noses. They also have massive thoraxes and lung capacity.
    - 0xEF 2y ago
      I can see that. Contrary to my personal feelings about my own nose, having grown up in a more Northern latitude where Winters were much, much harsher than what I experience now, there was a few key things I learned at an early age that stuck with me well into adulthood. Breathing through your nose in the cold while walking to class was one of them. I heard this a lot back then, the logic being as you propose; that it just gives the cold air a bit more time to warm before it reaches your core. Adding to that, you were also supposed to breathe slowly, rather than taking fast, gulping breathes. That just added to the reasons to avoid over-exerting yourself in the cold, which poses other risks. Other stuff had more to do with choice of clothing material, layering, etc, but that's not really applicable to this conversation. Interestingly, while it still does get cold where I live now, nobody really pays attention to these rules. I'd say the difference between the two areas is something like -5F on average, give or take. I am not sure how significant that is.
      - lproven 2y ago
        > Breathing through your nose in the cold while walking to class was one of them. After extensive nasal surgery in 2009 this became an option for me again, after over 20 years when it wasn't. I discovered a less-discussed rider: yes, it seems gentler on the lungs to breathe in through your nose in sub-zero weather, but there is a condition: you should breathe out through your nose as well. Exhaling warms the structures in the nose so it can warm the next inhalation. But, for me, that same sub-zero weather often causes my nose to make more mucus -- so breathing both in and out means a lot more use of a handkerchief, or a nasty snotty moustache. It's sometimes simply not worth it. :-/
cyrillite 2y ago
Respiratory efficiency is a pillar of health and performance, from sleep to hunting and fighting. I wouldn’t be surprised to find that marginal gains make a big difference and can be passed on.
lm28469 2y ago
> How can better air lead to higher numbers of successful offspring or fatalities? Try running XX hours after an antelope and report back, most animals aren't optimised for long distance, humans are, you can hunt most things by following them and waiting for them to collapse, surely having better air intake helps. It might be something as dumb as more antelope meat = more social points = you get to bang more. Why do 70%+ of the world population has brown eyes ? It offer marginal UV resistance but nobody becomes blind or sterile because they have blue eyes, certainly not before they can reproduce. Chances of reproduction can also be dictated by other things like attractiveness, and these are also very dependant on cultures and time periods.
- DiscourseFan 2y ago
  Its more like if your tribe has access to more meat they can produce more offspring. I wouldn't think of this in terms of individual prowess.
  - BurningFrog 2y ago
    Pretty sure the best hunter gets the most kids on average.
    - DiscourseFan 2y ago
      Source?
      - BurningFrog 2y ago
        Just common sense. The guy who brings home the most food will have the most surviving children. He will also be very attractive to women.
        DiscourseFan 2y ago
        It was also "common sense" not so long ago that the earth was the center of the universe. You're engaging with me disingenuously.
DrScientist 2y ago
Nose filters, and adjusts air temperature and humidity - it's not just a passive in/out hole. Evaporation is a big factor in both controlling temperature and water retention/loss ( that's why dogs pant in hot weather ). Remember the surface of your lungs are topologically on the outside - they are large and wet and are sensitive to both physical dust etc as well as potential infection. The nose design has to find the best balance across all these factors ( as well as being important in the sense of smell ).
wiether 2y ago
Silly suggestions related to snoring: - harder to find mating partner before earplugs were inventend - easier for your enemies/predators to catch you in your sleep
SamBam 2y ago
The article mentions an increase in upper respiratory tract infections in the air being breathed in is not humid enough. The hypothesis seems to be that in drier climates, humans need longer noses to increase the humidity of the air to an optimal level.

justlikereddit 2y ago

[flagged]

nothrowaways 2y ago
This is how our understanding about the world moves forward.

onetokeoverthe 2y ago

[flagged]

temptemptemp111 2y ago

[dead]

nomoreusernames 2y ago

[dead]

metalman 2y ago

There are a large amount of enviromental adaptations in many human populations, a lot of them to do with enzimatic adaptations. Climate as a term in this context is only usefull if you include, everything, diet, the ability to pass certain contaminents, such as high arsinic concentrations in water, vs binding say calcium. The full list, is, well, everything!, horribly complex, the nose ,perhaps working as a proxy indicator for a number of less visible adaptations, as succes in more extream environments is absolutly dependent on multiple adaptations, none of which is optional over generational time spans, as extream conditions, in an already extream environment, are going to eliminate marginal indivduals.

microtherion 2y ago

Weirdly, I saw this paper mentioned just this morning, in the context of an r/AskHistorians post discounting the possibility of an African origin for Olmecs. Sounded interesting, and then I saw it linked here.

dagenleg 2y ago
Same. Feels like we exist in a very small bubble doesn't it?

abricq 2y ago

On a slightly related topic, I remember to have seen an exposition where an artist was asked to represents what a human who has naturally evolved to survive a car crash might look like. And it has a cool / terrifying website: http://www.meetgraham.com.au/view-graham http://www.meetgraham.com.au/view-graham Quite fascinating topic to wonder about: how long will it take for the modern era to genetically change us ?

highcountess 2y ago
To answer your question, it already has changed us in many ways. You are not the only one who does not realize this though. It is in fact the prevailing position. We have diseases and genetic defects, among other impacts through modern behaviors and environments/toxins, which are also retained in the genetic mutational load. We even have a whole lot of energy and human activity working to counter evolutionary pressures and assure those accumulated mutational loads remain in the genetic code.
- amanaplanacanal 2y ago
  Fitness depends on the specific environment the creature is in. Environmental fitness for the ancestral environment when all humans were hunter-gatherers is not necessarily the same as fitness for living in an industrial society. Evolutionary pressure still works just fine.
spacebanana7 2y ago
Humans are beyond evolution. There's no meaningful selection pressure in our environment that kills people before reproductive age, so there's no reward for adaptations.
- mattigames 2y ago
  I have always considered that a bug, not a feature.
- svara 2y ago
  Totally wrong, killing humans is not required for evolution. Ignoring genetic drift and taking into account only natural selection, all that's needed is differences in fitness, i.e. differences in how much an individual contributes to the gene pool of future generations.

tpierce89 2y ago

I would like to see if there is a correlation between Sleep Apnea cases and nose shape to determine if there is a link between humans living in an area they are not adapted to and how that affects their ability to breathe normally.

ninetyninenine 2y ago
Sleep apnea usually comes from the back of the throat. It’s not a nose thing as much.
woolion 2y ago
I suspect the impact would be extremely small compared to BMI, so it would be likely that there would be a link because of some dependent variables.
- oremolten 2y ago
  I bet there is also a large correlation with computer/phone neck and posture
- hammock 2y ago
  Ok, what about looking at nose shape of diaspora that have historically (multigenerationally) high BMI? Not an expert but might suggest Inuit, some Pacific Islanders, Māori, west Africans maybe. How are their noses shaped and anything that might help with apnea?
- ratmeadow 2y ago
  BMI is a contributing factor, but so is neck and throat anatomy, regardless of weight. There are plenty of non-overweight people who have sleep apnea. And treatment sucks because so many doctors don't know anything past "you should lose weight".
BurningFrog 2y ago
People probably sleep in very similar conditions in all climates.

davidw 2y ago

Going to use this as a comeback next time my wife makes a comment: "I'm just well-adapted to certain climates, so there!"

boxed 2y ago

West African, but not East African? That seems like an enormous problem in itself.

nickdothutton 2y ago

Also there is a relatively new (5800 years ago) mutation somehow related to brain development, the ASPM gene. The mutation is somehow advantageous to the individual, but we don't yet know exactly why/how. https://en.wikipedia.org/wiki/ASPM_(gene)#Evolution https://en.wikipedia.org/wiki/ASPM_(gene)#Evolution

InfiniteLoup 2y ago

There is a rather distinct type of nose which I've only ever observed with people of Ukrainian ethnic descent. Now I wonder if that is in fact some type of adaptation to local climate because the people of the surrounding areas don't seem to have that nose shape to the same extent.

SamBam 2y ago

If I'm reading this right, the hypothesis seems to be that in drier climates, humans need longer noses (simplifying) to increase the humidity of the air to an optimal level. Did the authors propose a counter-evolutionary pressure, to favor a shorter nose in more humid environments? It's possible that the mechanism would be as simple as "it requires more resources to maintain a longer nose," but I'm also wondering if they suggested anything.

indulona 2y ago

[flagged]

Sam6late 2y ago

On a slightly related issue, I noticed that my nose gets bigger,in my photos, it turned out it was mostly irritation swelling due to pollution, while in a Nordic country with cleaner air quality, I noticed that is back to normal. And now I am always checking iqair.com- and it says:"PM2.5 concentration is currently 3.6 times the World Health Organization annual PM2.5 guideline value.

idunnoman1222 2y ago

Do people with bigger noses have fewer upper respiratory tract infections or no?