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How about this re-phrasing: The most terrifying thing about prions is that they are infectious but not life: they can't be "killed" in the normal sense While

by pohl 11y ago

How about this re-phrasing: The most terrifying thing about prions is that they are infectious but not life: they can't be "killed" in the normal sense While viruses are generally not considered to be alive, they are considered to be instances of life, aren't they?

djsumdog 11y ago
...and many viruses can't survive outside a host. Their structure can break apart. IIRC HIV is like that.
- ars 11y ago
  That doesn't make them special. Fish can not survive without a host either (i.e. water).
  - ekianjo 11y ago
    It makes them special since bacteria can survive in numerous environments where viruses are destroyed.
  - noselasd 11y ago
    Water is not a host in the biological sense.
- pohl 11y ago
  That doesn't quite capture it. There are lots of obligate parasites that aren't viruses, right? https://en.wikipedia.org/wiki/Obligate_parasite https://en.wikipedia.org/wiki/Obligate_parasite
Double_Cast 11y ago
Of the 6 or 7 criteria biologists usually use to define life, viruses often fall short. E.g. viruses do not have their own metabolism. Everyone has their own definition though. I remember reading a novel where life was defined simply as heredity, mutation, and adaptation. The second definition makes more sense to me, and implicitly includes viruses.