4 ms·

Traits tend to go away when not needed. Pigment is essentially an appendix. EDIT: Okay, wisdom teeth then. Or teeth in general, which are gradually disappear

Traits tend to go away when not needed. Pigment is essentially an appendix. EDIT: Okay, wisdom teeth then. Or teeth in general, which are gradually disappearing.

thaumaturgy 17y ago
...in that the appendix was recently discovered to have a useful function as a backup store for intestinal bacteria in case something killed off all the good stuff in your gut?
- gort 17y ago
  (Slightly off topic, but isn't the benefit of the appendix outweighed by how often if becomes infected, etc?)
  - roqetman 17y ago
    Only with the "western" diet. You'll see much fewer cases of appendicitis amongst those who don't eat the overly-rich western diet. So in my opinion, this is cultural, not genetic.
    - xiaoma 17y ago
      My father had appendicitis before the age of 25, despite a relatively simple diet. His father, who lived through WWII food rationing, had appendicitis, too. He wouldn't have survived without being cut open and treated with penicillin. For obvious reasons, I wish this were caused by culture, but genetics is almost certainly at work.
      - eru 17y ago
        Culture saved them in this case.
  - pohl 17y ago
    Are we really at liberty to disagree with the replicators on that one? If it really outweighed it, it would have been the end of the line.
    - gort 17y ago
      Removing the appendix would presumably take multiple mutations that would have other, possibly harmful effects as well. So it can't really happen overnight.
      - pohl 17y ago
        In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce. My son was born 3 weeks ago. My appendix could do me in tomorrow and the genes that express for it will likely go on.
        gort 17y ago
        In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce. Not at all; it just needs to reduce the average number of children the average person has. Any mutation that makes it "less troublesome" on average would be favoured.
        pohl 17y ago
        Fair point. I thought it would be fun to compare the mortality rate with an issue with another organ that has slim chance of going away: the pancreas. It looks like the appendix is more-or-less a trouble-free organ in comparison. I wouldn't place any bets on the emergence of an appendix-free homo sapien offshoot any time soon. http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=appendicitis http://www.wolframalpha.com/input/?i=appendicitis
        lionhearted 17y ago
        > Any mutation that makes it "less troublesome" on average would be favoured. That's correct, but, from my understanding, revolutionary mutations are orders of magnitude less likely to happen than evolutionary mutations. Everyone has an appendix, so there's no natural selection pressure where non-appendix people are breeding to further the spread of non-appendix humans. Just thinking out loud here - I reckon the way it would have to go would be if the appendix was a significant disadvantage, and people with a less sensitive/smaller/less prominent/something-like-that appendix were able to survive more easily or have more children on average, then you might selection pressures moving towards a less prominent and eventually no appendix. It could happen, but it'd take a long time. Actually, one that fascinates me is what effect modern medicine and technology will have on evolution. Greater mobility is seeing children with a more mixed and diverse hereditary mix. Beyond that though, longer life cycles and better medical treatment might mean both slower and less evolution. I'd expect a lot of positive effects from interbreeding of different peoples over the next 500 years, but I reckon, sadly, that things like aggression won't be genetically bred out of us any time soon by being selected for less. Interesting stuff to think about.
- BearOfNH 17y ago
  [Citation Needed]
  - thaumaturgy 17y ago
    [1]: http://www.msnbc.msn.com/id/21153898/ http://www.msnbc.msn.com/id/21153898/
gort 17y ago
I doubt it; isn't it providing protection from UV-caused skin cancer and such? [Edit: I took you to mean that pigment was generally not beneficial, but probably you meant only in certain environments, which would be fair enough.]
- kingkongreveng_ 17y ago
  Other way around. Darker skin in North America is correlated to more cancer, due to the consequent vitamin D deficiency. Most of the population is now vitamin D deficient because people don't spend much time outside.
  - gort 17y ago
    I said specifically skin cancer. Naturally there's a balance between getting vitamin D and avoiding harmful UV. So the best skin tone to have differs in different environments (hence the gradual cline in skin tones over the world).
    - pasbesoin 17y ago
      I don't have details at hand to cite, but I recall encountering some recent news of research that may place in question equating a simple measure of sun exposure to elevated risk for skin cancer. (I didn't look at in depth, and my memory could be somewhat faulty.) It may not be simple quantity of exposure, but rather severe sunburns that most elevate risk. If one is outside regularly and acclimatized, these severe burns are less likely to occur. Perhaps someone else will have a more detailed comment on this. Of course, one's pigmentation will also influence the likelihood of sunburn, although dark pigmentation does not entirely prevent burning. EDIT: Just read InclinedPlane's comment, above, which mentions the same concern with sunburn.
- InclinedPlane 17y ago
  Actually you have it backwards. Melanin is considered extremely important by the body, some people have high latent melanin levels but all people regardless of race are able to darken their skin color via tanning (exposure to the sun triggering melanin release). Darker skin protects you from being sun burned, which is harmful and can even be fatal (leading to heat exhaustion, heat stroke, etc.) The body considers melanin production so important that some of the natural checks and balances against cancer are inhibited in melanin generation cells, which is why skin cancer is fairly common compared to other types of cancer.
deleted 17y ago
[deleted]

Traits tend to go away when not needed. Pigment is essentially an appendix. EDIT: Okay, wisdom teeth then. Or teeth in general, which are gradually disappearing.

thaumaturgy 17y ago

...in that the appendix was recently discovered to have a useful function as a backup store for intestinal bacteria in case something killed off all the good stuff in your gut?

gort 17y ago
(Slightly off topic, but isn't the benefit of the appendix outweighed by how often if becomes infected, etc?)
- roqetman 17y ago
  Only with the "western" diet. You'll see much fewer cases of appendicitis amongst those who don't eat the overly-rich western diet. So in my opinion, this is cultural, not genetic.
  - xiaoma 17y ago
    My father had appendicitis before the age of 25, despite a relatively simple diet. His father, who lived through WWII food rationing, had appendicitis, too. He wouldn't have survived without being cut open and treated with penicillin. For obvious reasons, I wish this were caused by culture, but genetics is almost certainly at work.
    - eru 17y ago
      Culture saved them in this case.
- pohl 17y ago
  Are we really at liberty to disagree with the replicators on that one? If it really outweighed it, it would have been the end of the line.
  - gort 17y ago
    Removing the appendix would presumably take multiple mutations that would have other, possibly harmful effects as well. So it can't really happen overnight.
    - pohl 17y ago
      In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce. My son was born 3 weeks ago. My appendix could do me in tomorrow and the genes that express for it will likely go on.
      - gort 17y ago
        In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce. Not at all; it just needs to reduce the average number of children the average person has. Any mutation that makes it "less troublesome" on average would be favoured.
        pohl 17y ago
        Fair point. I thought it would be fun to compare the mortality rate with an issue with another organ that has slim chance of going away: the pancreas. It looks like the appendix is more-or-less a trouble-free organ in comparison. I wouldn't place any bets on the emergence of an appendix-free homo sapien offshoot any time soon. http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=pancreas+cancer http://www.wolframalpha.com/input/?i=appendicitis http://www.wolframalpha.com/input/?i=appendicitis
        lionhearted 17y ago
        > Any mutation that makes it "less troublesome" on average would be favoured. That's correct, but, from my understanding, revolutionary mutations are orders of magnitude less likely to happen than evolutionary mutations. Everyone has an appendix, so there's no natural selection pressure where non-appendix people are breeding to further the spread of non-appendix humans. Just thinking out loud here - I reckon the way it would have to go would be if the appendix was a significant disadvantage, and people with a less sensitive/smaller/less prominent/something-like-that appendix were able to survive more easily or have more children on average, then you might selection pressures moving towards a less prominent and eventually no appendix. It could happen, but it'd take a long time. Actually, one that fascinates me is what effect modern medicine and technology will have on evolution. Greater mobility is seeing children with a more mixed and diverse hereditary mix. Beyond that though, longer life cycles and better medical treatment might mean both slower and less evolution. I'd expect a lot of positive effects from interbreeding of different peoples over the next 500 years, but I reckon, sadly, that things like aggression won't be genetically bred out of us any time soon by being selected for less. Interesting stuff to think about.
BearOfNH 17y ago
[Citation Needed]
- thaumaturgy 17y ago
  [1]: http://www.msnbc.msn.com/id/21153898/ http://www.msnbc.msn.com/id/21153898/

gort 17y ago

I doubt it; isn't it providing protection from UV-caused skin cancer and such? [Edit: I took you to mean that pigment was generally not beneficial, but probably you meant only in certain environments, which would be fair enough.]

kingkongreveng_ 17y ago
Other way around. Darker skin in North America is correlated to more cancer, due to the consequent vitamin D deficiency. Most of the population is now vitamin D deficient because people don't spend much time outside.
- gort 17y ago
  I said specifically skin cancer. Naturally there's a balance between getting vitamin D and avoiding harmful UV. So the best skin tone to have differs in different environments (hence the gradual cline in skin tones over the world).
  - pasbesoin 17y ago
    I don't have details at hand to cite, but I recall encountering some recent news of research that may place in question equating a simple measure of sun exposure to elevated risk for skin cancer. (I didn't look at in depth, and my memory could be somewhat faulty.) It may not be simple quantity of exposure, but rather severe sunburns that most elevate risk. If one is outside regularly and acclimatized, these severe burns are less likely to occur. Perhaps someone else will have a more detailed comment on this. Of course, one's pigmentation will also influence the likelihood of sunburn, although dark pigmentation does not entirely prevent burning. EDIT: Just read InclinedPlane's comment, above, which mentions the same concern with sunburn.
InclinedPlane 17y ago
Actually you have it backwards. Melanin is considered extremely important by the body, some people have high latent melanin levels but all people regardless of race are able to darken their skin color via tanning (exposure to the sun triggering melanin release). Darker skin protects you from being sun burned, which is harmful and can even be fatal (leading to heat exhaustion, heat stroke, etc.) The body considers melanin production so important that some of the natural checks and balances against cancer are inhibited in melanin generation cells, which is why skin cancer is fairly common compared to other types of cancer.

deleted 17y ago

[deleted]