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peter lindsay

Physics Teacher,


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A universal definition of life.

Any entity that has the ability to store and exchange information autonomously.
Perhaps as we move through the next millenium we will need a definition of life that is this general. It may be needed to classify artificial life or to classify alien life. We may find life forms so different to ourselves that the only recognisable feature is information management. It might also help us to identify the point at which a person is no longer alive.

Topics: afterlife death life

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  • Aug 26 2012: Hi Adrinn

    I believe a sterile cloned animal would be alive based on my classification of anything that carries out cellular respiration being alive, I don't believe the ability to reproduce is necessary for a classification of living however it can be used as a guiding principle for classifying acellular forms, by which I mean that reproduction is a common trait amongst cellularly respiring life forms and therefor may help guide our classification of non-cellularly respiring forms.

    Essentially, if some acellular form had the same properties as a cellularly respiring life form however was not a cell, that would be a pretty compelling argument to classify it as an acellular life form.

    Here's an interesting one for you, what about Craig Venter's artificial bacteria cell? If you haven't seen the TED video do check it out, very good stuff!
    • Aug 27 2012: Hi Andrew

      If you take away the capability of reproduction from a cell, then you get a form which is alive for maybe a few weeks then it is no more and never will be because we took its livelihood away. So yes it was alive. But not live. When you say it is alive then it implies the fact that it was brought to life. But when you say live than it means that it is capable of existing. And this cell is not, because we took away its reproductive function. After ran its course it will die. If you take away the reproductive function by host, from the virus, it will be no more because the reproduction itself is the life of the virus. The mechanism of reproduction is came to be in the universe, so forms that are more fragile than a granite slab can keep existing but not by keeping one individual alive but rather being able to reproduce and pass down itself to another. We must argue this “what is life and living” question not by one individual from a herd but by clusters. If a form came to existence by the universe trials and errors and it is capable to sustain itself by interacting with its surrounding and reproduce itself to be able to keep the interaction going then it is a living form. When a form came to existence by the universe trials and errors and it is capable to sustain itself by interacting with its surrounding but no longer (as a whole species) or never was able to reproduce, it is alive but not an ongoing living form. And most likely we will never meet this form in an alive state because it will die very quickly. And it will because of its fragile nature.
      To look at the prion. I would not consider it alive since it does not pass the info to the next one how to create another prion. Maybe in a few million years it will but not just yet.

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