7 ms·

More and more humans are growing an extra artery, showing we're still evolving

71 points by donatzsky 5y ago

idiotsecant 5y ago
No, it's showing that we maintain the extra artery. There is no reason to believe this is an evolutionary change - there are plenty of hormonal and other environmental factors that could be contributing as well.
- crazygringo 5y ago
  Exactly -- if the rate of change is as high as they state -- from 10% to 30% of people in a little over a century -- it seems it would be essentially impossible for it to be the result of natural selection or genetic change. As you say, the obvious explanation is hormonal/environmental factors.
  - gpsx 5y ago
    Yes - in order to have a change be that fast it would have to be something that makes those people dramatically better at surviving, like X-men type mutations, or reproducing. I don't think the change of this blood vessel is really turning the tables between survival and death, or making these people that much more successful at reproducing. But with the prevalence of online dating these days, maybe it is a big help by allow people to navigate faster? /s
    - Osiris 5y ago
      A mutation will also stick around if it doesn't prevent the person from reproducing. That can still be considered evolution even if it doesn't provide an obvious benefit.
      - nvrspyx 5y ago
        Just to clarify, the parent comment was stating that for a change (read: evolution) to be that _fast_, it would have to help either survivability or reproduction. In other words, increasing survivability or reproduction speeds up a mutation's proliferation throughout the species.
    - robocat 5y ago
      > makes those people dramatically better at surviving Better at reproducing. Death after reproduction has much less effect on evolution than death before reproduction. It is unfortunate that it is so often misstated (I am guessing you already know the difference, but I want to clarify it for those who are not so aware). As an aside, I think the article is complete and utter bollocks.
      - gpsx 5y ago
        I am guessing this is misstated because so often lack of survival is the reason there is less reproduction. But yes, it comes down to who passes their genetic material to the most offspring.
  - enkid 5y ago
    What do you mean by environmental factors? The environment drives evolution, so changes in the environment would change who survives, which would lead to evolution. If it is an environmental factor that led to selection of individuals having this vein being more likely to propagate, that would still be evolution. This also some very simple scenarios that could lead to such a pressure, like the artery having some minor benefit in reproduction, but a disease we eradicated would disproportionately kill people with the artery.
    - deleted 5y ago
      [deleted]
    - OJFord 5y ago
      They mean within a lifespan factors, like pollution, diet, lifestyle, etc.
    - TrispusAttucks 5y ago
      Evolution is of a change in the genes. Environmental factors can influence the expression of a gene (think Testosterone or Estrogen) without a change of genetics. The change in expression over time and participant count the study highlights is not compatible with a natural selection driven evolution.
      - enkid 5y ago
        But this would still present an environmental pressure, which would drive evolutionary change. Maybe not this specific gene, but if the environment is driving changes to our anatomy, it will drive changes in to reproductive fit. Maybe not this specific artery, but some other anatomical change.
      - beerandt 5y ago
        Epigenetics is the missing term here.
- evancox100 5y ago
  Agreed, pretty clearly an epigenetic or environmental change, not an evolutionary DNA change.
- edgyquant 5y ago
  I mean, how is that not potentially evolution?
  - idiotsecant 5y ago
    Because non-genetically derived influences are not evolution?
    - rixed 5y ago
      So what was Darwin writing about, one century before DNA was discovered, if not evolution?
      - MattPalmer1086 5y ago
        DNA is just a particular mechanism of inheritance. You don't need to know about DNA specifically to posit a theory of evolution (inheritance, variation, natural selection).
        rixed 5y ago
        My point exactly.
mrkramer 5y ago
Evolution is constant since environment we live in is always changing and we need to adapt to it. Extra artery is an anatomical variation[1] because in order to evolve random mutations are happening and whatever works is passed to offspring. For example this article[2] explains Alan Turing 's Turing pattern[3] and pattern variation of denticles, the toothlike protrusions that cover the skin of sharks. The article says "Nature tends to invent something once, and then plays variations on that theme." That's true because variation is a way for nature to trial and error certain solutions until good enough solution is found. [1] https://en.wikipedia.org/wiki/Anatomical_variation https://en.wikipedia.org/wiki/Anatomical_variation [2] https://nautil.us/issue/68/context/how-alan-turing-deciphered-shark-skin https://nautil.us/issue/68/context/how-alan-turing-deciphere... [3] https://en.wikipedia.org/wiki/Turing_pattern https://en.wikipedia.org/wiki/Turing_pattern
ozarkerD 5y ago
Given that there’s so much technology available to keep humans alive, will human evolution continue? It seems like it could give rise to a lot of negative traits propagating that would usually mean death before producing offspring a couple hundred years ago.
- thunderbird120 5y ago
  Evolution is the propagation of traits of individuals who survived and reproduced and whose offspring survived and reproduced. In a modern developed country survival is less uncertain but reproduction of healthy individuals is actually more uncertain as can be seen by looking at the birth rates in essentially any developed country. As a result, traits that affect certain behaviors, such as underlying desire to reproduce, are likely under more intense selection pressure now than any traits in all of human history.
- thaumasiotes 5y ago
  > will human evolution continue? This is a nonsensical question; it isn't possible to have reproduction without evolution.
  - echelon 5y ago
    > This is a nonsensical question; it isn't possible to have reproduction without evolution. It's possible to have reproduction without evolution. We have monoclonal immunocompromised mice with fixed genomes. We created them.
    - thaumasiotes 5y ago
      You say that like clonal organisms aren't out in the wild, evolving. It is not possible to have reproduction without evolution.
      - echelon 5y ago
        Monoclonal mice aren't out in the wild. Some of the lines are incapable of breeding, yet we keep making them.
aksss 5y ago
This is about a condition called Persistent Median Artery or PMA, and it's a bit of a rabbit hole. Evidently having this condition is associated with increasing your odds or the impact of carpal tunnel syndrome. PMA can manifest in a few different configurations, like depth to which it extends in the hand, thickness, etc. Here's an interesting read with pictures of dissected forearms showing PMA variants. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327784/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327784/
kafkaIncarnate 5y ago
More and more people are also getting heart attacks. Coincidence? I think not! Evolution is selecting humans out!
- dylan604 5y ago
  I think human diet is selecting humans out. Nature didn't create food products, humans did. We took food, and created a product. How absolutely mind boggling dumb that just sounds to me. Food doesn't have ingredients; food are ingredients.
  - bserge 5y ago
    Only those who can live on a diet of McDonald's and soft drinks will survive!
    - dylan604 5y ago
      I honestly wouldn't want to live in that world. Eating is something to be enjoyed not just to survive.
      - deleted 5y ago
        [deleted]
      - kafkaIncarnate 5y ago
        Already exists in rural America. At least you also have the option of Arby's or Casey's, with a side of Dollar General. If you're lucky you might get a Subway.
deleted 5y ago
[deleted]
benkuhn 5y ago
I'm not an evolutionary biologist, but it seems to me that the claimed magnitude of the change is wildly implausibly fast from an evolutionary perspective. I'm confused that neither the article, nor the paper it cites, addresses this. To go from 10% to 30% in ~5 generations, the median-artery-having population would have had to expand by (30/10)^(1/5) = 25% more than the non-median artery population over each generation. It just seems totally implausible that median artery carriers could have that much more offspring. This makes me pretty suspicious that the paper may be wrong.
- rixed 5y ago
  You could also suspect that your understanding of evolution is not 100% correct. Genes do not necessarily propagate in a population because they enhance reproduction. They can have no or very little influence but still propagate by chance. (Similarly, beneficial mutations can disappear from the genetic pool by chance). Lookup "genetic drift". By the time the environment does change (which can happen as quick or slow as one wants), the lucky genes are already spread in the population and may turn useful or detrimental to the individuals after that environmental change. Also, genetics is not the only driver for evolution.
sxg 5y ago
I really dislike these articles on pop-sci websites. It’s basically just another clickbait news site except it has the word “science” displayed everywhere to give itself slightly more legitimacy. This artery is just another normal variant. There are tons and tons of normal variants throughout the body including major central arteries (eg aberrant right subclavian, retropharyngeal carotids). The changing prevalence is likely more an artifact of data collecting than anything meaningful, just like most of the articles on these sites that gain any traction.
jacquesm 5y ago
Of course we are still evolving. It's just that the selection pressures applied are different now than they were in the past, and this doesn't look like something subject to selection pressure so I doubt it is an example of evolution in progress.
senectus1 5y ago
My dentist claims that the fact I was born without wisdom teeth is a sign of evolution as well. Apparently its increasingly more common. Happy to claim i'm more highly evolved than others :-P (yes I know evolution is small gradual changes not some superpower. its a joke people)
justsomeuser 5y ago
My understanding is that cell based life never stops evolving - it is a constant feedback loop with the environment to build organic tools to extract resources from the environment. It always makes me laugh when people have the concept that we humans are completely separate things from the species in the animal kingdom.

71 points by donatzsky 5y ago

No, it's showing that we maintain the extra artery. There is no reason to believe this is an evolutionary change - there are plenty of hormonal and other environmental factors that could be contributing as well.

crazygringo 5y ago
Exactly -- if the rate of change is as high as they state -- from 10% to 30% of people in a little over a century -- it seems it would be essentially impossible for it to be the result of natural selection or genetic change. As you say, the obvious explanation is hormonal/environmental factors.
- gpsx 5y ago
  Yes - in order to have a change be that fast it would have to be something that makes those people dramatically better at surviving, like X-men type mutations, or reproducing. I don't think the change of this blood vessel is really turning the tables between survival and death, or making these people that much more successful at reproducing. But with the prevalence of online dating these days, maybe it is a big help by allow people to navigate faster? /s
  - Osiris 5y ago
    A mutation will also stick around if it doesn't prevent the person from reproducing. That can still be considered evolution even if it doesn't provide an obvious benefit.
    - nvrspyx 5y ago
      Just to clarify, the parent comment was stating that for a change (read: evolution) to be that _fast_, it would have to help either survivability or reproduction. In other words, increasing survivability or reproduction speeds up a mutation's proliferation throughout the species.
  - robocat 5y ago
    > makes those people dramatically better at surviving Better at reproducing. Death after reproduction has much less effect on evolution than death before reproduction. It is unfortunate that it is so often misstated (I am guessing you already know the difference, but I want to clarify it for those who are not so aware). As an aside, I think the article is complete and utter bollocks.
    - gpsx 5y ago
      I am guessing this is misstated because so often lack of survival is the reason there is less reproduction. But yes, it comes down to who passes their genetic material to the most offspring.
- enkid 5y ago
  What do you mean by environmental factors? The environment drives evolution, so changes in the environment would change who survives, which would lead to evolution. If it is an environmental factor that led to selection of individuals having this vein being more likely to propagate, that would still be evolution. This also some very simple scenarios that could lead to such a pressure, like the artery having some minor benefit in reproduction, but a disease we eradicated would disproportionately kill people with the artery.
  - deleted 5y ago
    [deleted]
  - OJFord 5y ago
    They mean within a lifespan factors, like pollution, diet, lifestyle, etc.
  - TrispusAttucks 5y ago
    Evolution is of a change in the genes. Environmental factors can influence the expression of a gene (think Testosterone or Estrogen) without a change of genetics. The change in expression over time and participant count the study highlights is not compatible with a natural selection driven evolution.
    - enkid 5y ago
      But this would still present an environmental pressure, which would drive evolutionary change. Maybe not this specific gene, but if the environment is driving changes to our anatomy, it will drive changes in to reproductive fit. Maybe not this specific artery, but some other anatomical change.
    - beerandt 5y ago
      Epigenetics is the missing term here.
evancox100 5y ago
Agreed, pretty clearly an epigenetic or environmental change, not an evolutionary DNA change.
edgyquant 5y ago
I mean, how is that not potentially evolution?
- idiotsecant 5y ago
  Because non-genetically derived influences are not evolution?
  - rixed 5y ago
    So what was Darwin writing about, one century before DNA was discovered, if not evolution?
    - MattPalmer1086 5y ago
      DNA is just a particular mechanism of inheritance. You don't need to know about DNA specifically to posit a theory of evolution (inheritance, variation, natural selection).
      - rixed 5y ago
        My point exactly.

mrkramer 5y ago

Evolution is constant since environment we live in is always changing and we need to adapt to it. Extra artery is an anatomical variation[1] because in order to evolve random mutations are happening and whatever works is passed to offspring. For example this article[2] explains Alan Turing 's Turing pattern[3] and pattern variation of denticles, the toothlike protrusions that cover the skin of sharks. The article says "Nature tends to invent something once, and then plays variations on that theme." That's true because variation is a way for nature to trial and error certain solutions until good enough solution is found. [1] https://en.wikipedia.org/wiki/Anatomical_variation https://en.wikipedia.org/wiki/Anatomical_variation [2] https://nautil.us/issue/68/context/how-alan-turing-deciphered-shark-skin https://nautil.us/issue/68/context/how-alan-turing-deciphere... [3] https://en.wikipedia.org/wiki/Turing_pattern https://en.wikipedia.org/wiki/Turing_pattern

ozarkerD 5y ago

Given that there’s so much technology available to keep humans alive, will human evolution continue? It seems like it could give rise to a lot of negative traits propagating that would usually mean death before producing offspring a couple hundred years ago.

thunderbird120 5y ago
Evolution is the propagation of traits of individuals who survived and reproduced and whose offspring survived and reproduced. In a modern developed country survival is less uncertain but reproduction of healthy individuals is actually more uncertain as can be seen by looking at the birth rates in essentially any developed country. As a result, traits that affect certain behaviors, such as underlying desire to reproduce, are likely under more intense selection pressure now than any traits in all of human history.
thaumasiotes 5y ago
> will human evolution continue? This is a nonsensical question; it isn't possible to have reproduction without evolution.
- echelon 5y ago
  > This is a nonsensical question; it isn't possible to have reproduction without evolution. It's possible to have reproduction without evolution. We have monoclonal immunocompromised mice with fixed genomes. We created them.
  - thaumasiotes 5y ago
    You say that like clonal organisms aren't out in the wild, evolving. It is not possible to have reproduction without evolution.
    - echelon 5y ago
      Monoclonal mice aren't out in the wild. Some of the lines are incapable of breeding, yet we keep making them.

aksss 5y ago

This is about a condition called Persistent Median Artery or PMA, and it's a bit of a rabbit hole. Evidently having this condition is associated with increasing your odds or the impact of carpal tunnel syndrome. PMA can manifest in a few different configurations, like depth to which it extends in the hand, thickness, etc. Here's an interesting read with pictures of dissected forearms showing PMA variants. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327784/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327784/

kafkaIncarnate 5y ago

More and more people are also getting heart attacks. Coincidence? I think not! Evolution is selecting humans out!

dylan604 5y ago
I think human diet is selecting humans out. Nature didn't create food products, humans did. We took food, and created a product. How absolutely mind boggling dumb that just sounds to me. Food doesn't have ingredients; food are ingredients.
- bserge 5y ago
  Only those who can live on a diet of McDonald's and soft drinks will survive!
  - dylan604 5y ago
    I honestly wouldn't want to live in that world. Eating is something to be enjoyed not just to survive.
    - deleted 5y ago
      [deleted]
    - kafkaIncarnate 5y ago
      Already exists in rural America. At least you also have the option of Arby's or Casey's, with a side of Dollar General. If you're lucky you might get a Subway.

deleted 5y ago

[deleted]

benkuhn 5y ago

I'm not an evolutionary biologist, but it seems to me that the claimed magnitude of the change is wildly implausibly fast from an evolutionary perspective. I'm confused that neither the article, nor the paper it cites, addresses this. To go from 10% to 30% in ~5 generations, the median-artery-having population would have had to expand by (30/10)^(1/5) = 25% more than the non-median artery population over each generation. It just seems totally implausible that median artery carriers could have that much more offspring. This makes me pretty suspicious that the paper may be wrong.

rixed 5y ago
You could also suspect that your understanding of evolution is not 100% correct. Genes do not necessarily propagate in a population because they enhance reproduction. They can have no or very little influence but still propagate by chance. (Similarly, beneficial mutations can disappear from the genetic pool by chance). Lookup "genetic drift". By the time the environment does change (which can happen as quick or slow as one wants), the lucky genes are already spread in the population and may turn useful or detrimental to the individuals after that environmental change. Also, genetics is not the only driver for evolution.

sxg 5y ago

I really dislike these articles on pop-sci websites. It’s basically just another clickbait news site except it has the word “science” displayed everywhere to give itself slightly more legitimacy. This artery is just another normal variant. There are tons and tons of normal variants throughout the body including major central arteries (eg aberrant right subclavian, retropharyngeal carotids). The changing prevalence is likely more an artifact of data collecting than anything meaningful, just like most of the articles on these sites that gain any traction.

jacquesm 5y ago

Of course we are still evolving. It's just that the selection pressures applied are different now than they were in the past, and this doesn't look like something subject to selection pressure so I doubt it is an example of evolution in progress.

senectus1 5y ago

My dentist claims that the fact I was born without wisdom teeth is a sign of evolution as well. Apparently its increasingly more common. Happy to claim i'm more highly evolved than others :-P (yes I know evolution is small gradual changes not some superpower. its a joke people)

justsomeuser 5y ago

My understanding is that cell based life never stops evolving - it is a constant feedback loop with the environment to build organic tools to extract resources from the environment. It always makes me laugh when people have the concept that we humans are completely separate things from the species in the animal kingdom.