5 ms·

MIT researchers solve mystery of the 1918 "Spanish Flu" pandemic

11 points by pmikal 17y ago

steve19 17y ago
Isn't a flu virus like spanish flu an evolutionary mistake? Killing your host is a bad way to passed on. The penalty for the "mistake" is that the strain, or at least its notable features, no longer exist.
- dflock 17y ago
  It depends on how quickly you kill them and how you do it. Cholera victims go out in a flood of infectious watery diarrhea, thus spreading the virus to people in the vicinity and into the ground water, passing the infection along. Ebola does something horribly similar, except with blood and liquefied internal organs. The diarrhea you get with cholera is mostly your body trying to flush out the bacteria and toxins from your gut. Cholera has evolved to exploit and exacerbate this defense mechanism to spread itself. Sneezing is that same principle, for respiratory infections. These dramatic death throws can be viewed as a very aggressive means of the infection passing itself along, after having completely exhausted the capacity of the current host to produce more virus or bacteria. Even though these are both extremely lethal and fast acting diseases, they're both successful, evolutionarily speaking. If there was a flu strain that made you sneeze so much that you eventually died from it (dehydration, hemorrhage?), this would be similar. As it is, it's generally your immune system going nuclear, an opportunistic infection, underlying poor health or a combination that kills you with influenza. Quite a lot of the pandemic potential of diseases depends on us and the opportunities we give them. Ebola has thus far proved too lethal and too quick to spread very widely - and because it's a terrifying disease, we've cracked down on it very hard. Cholera - which is actually more lethal and even faster acting than Ebola - was the scourge of the 19th century, killing tens of millions of people, before we figured out about pubic health and sanitation, taking away it's opportunities. So, no. Killing people isn't an evolutionary mistake for an infectious organism. It's an evolutionary adaptation - a way of pumping out as many new bacteria or viruses into the environment as fast as possible and then moving on, before the hosts immune system catches up with you. If you take it easy and go for the slow burn, generally the hosts immune system will wipe you out. If you want to do that, then you need a different evolutionary adaptation to evade the immune system for long periods, like HIV does.
  - fauigerzigerk 17y ago
    But the common cold is slow, non-lethal and still ubiquitous. It seems unclear to me what success really means in this context.
    - anamax 17y ago
      Success means "not extinct".
      - fauigerzigerk 17y ago
        Yes but among those who survive, is the common cold virus more successful than ebola? I don't think there's a good answer to that.
        anamax 17y ago
        That's because "more successful" is not a good question. Unless one or the other dies out, they're both successful and that's all that you can really say. The common cold is more common than Ebola. That may help the common cold survive longer. If it does, and we suspect that it does, then "common" was useful. If, on the other hand, that "commonality" makes us so mad that we go all out to kill it and succeed (like we probably have with small pox and might soon with polio), "common" worked against it.
        fauigerzigerk 17y ago
        I agree with what you say, but I was trying make an entirely different point, which is that I don't think success is the right word to describe anything related to evolution. Success implies goals and evolution has no goals. A particular species surviving or not is just like rolling a die and observing that the 3 has come up and the other numbers didn't. It's useless to say that 4 wasn't successful. Nobody would say that, but when it comes to evolution people start to talk about success as if nature had intentions.
        17y ago
- fauigerzigerk 17y ago
  To make a mistake requires a goal. I don't think evolution has goals. It's simply an after the fact observation we can make that particular species survived and others didn't. This is not the result of any intention or goal in my view and therefore it's no mistake when a species doesn't survive. But I don't mean to be nitpicky. I know what you meant and it's a good question. I believe what you refer to is the reason why extremely virulent viruses like ebola don't spread all across the world. They kill their host and themselves very quickly.

11 points by pmikal 17y ago

Isn't a flu virus like spanish flu an evolutionary mistake? Killing your host is a bad way to passed on. The penalty for the "mistake" is that the strain, or at least its notable features, no longer exist.

dflock 17y ago
It depends on how quickly you kill them and how you do it. Cholera victims go out in a flood of infectious watery diarrhea, thus spreading the virus to people in the vicinity and into the ground water, passing the infection along. Ebola does something horribly similar, except with blood and liquefied internal organs. The diarrhea you get with cholera is mostly your body trying to flush out the bacteria and toxins from your gut. Cholera has evolved to exploit and exacerbate this defense mechanism to spread itself. Sneezing is that same principle, for respiratory infections. These dramatic death throws can be viewed as a very aggressive means of the infection passing itself along, after having completely exhausted the capacity of the current host to produce more virus or bacteria. Even though these are both extremely lethal and fast acting diseases, they're both successful, evolutionarily speaking. If there was a flu strain that made you sneeze so much that you eventually died from it (dehydration, hemorrhage?), this would be similar. As it is, it's generally your immune system going nuclear, an opportunistic infection, underlying poor health or a combination that kills you with influenza. Quite a lot of the pandemic potential of diseases depends on us and the opportunities we give them. Ebola has thus far proved too lethal and too quick to spread very widely - and because it's a terrifying disease, we've cracked down on it very hard. Cholera - which is actually more lethal and even faster acting than Ebola - was the scourge of the 19th century, killing tens of millions of people, before we figured out about pubic health and sanitation, taking away it's opportunities. So, no. Killing people isn't an evolutionary mistake for an infectious organism. It's an evolutionary adaptation - a way of pumping out as many new bacteria or viruses into the environment as fast as possible and then moving on, before the hosts immune system catches up with you. If you take it easy and go for the slow burn, generally the hosts immune system will wipe you out. If you want to do that, then you need a different evolutionary adaptation to evade the immune system for long periods, like HIV does.
- fauigerzigerk 17y ago
  But the common cold is slow, non-lethal and still ubiquitous. It seems unclear to me what success really means in this context.
  - anamax 17y ago
    Success means "not extinct".
    - fauigerzigerk 17y ago
      Yes but among those who survive, is the common cold virus more successful than ebola? I don't think there's a good answer to that.
      - anamax 17y ago
        That's because "more successful" is not a good question. Unless one or the other dies out, they're both successful and that's all that you can really say. The common cold is more common than Ebola. That may help the common cold survive longer. If it does, and we suspect that it does, then "common" was useful. If, on the other hand, that "commonality" makes us so mad that we go all out to kill it and succeed (like we probably have with small pox and might soon with polio), "common" worked against it.
        fauigerzigerk 17y ago
        I agree with what you say, but I was trying make an entirely different point, which is that I don't think success is the right word to describe anything related to evolution. Success implies goals and evolution has no goals. A particular species surviving or not is just like rolling a die and observing that the 3 has come up and the other numbers didn't. It's useless to say that 4 wasn't successful. Nobody would say that, but when it comes to evolution people start to talk about success as if nature had intentions.
        17y ago
fauigerzigerk 17y ago
To make a mistake requires a goal. I don't think evolution has goals. It's simply an after the fact observation we can make that particular species survived and others didn't. This is not the result of any intention or goal in my view and therefore it's no mistake when a species doesn't survive. But I don't mean to be nitpicky. I know what you meant and it's a good question. I believe what you refer to is the reason why extremely virulent viruses like ebola don't spread all across the world. They kill their host and themselves very quickly.