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Jen's picture

In trying to classify life,

In trying to classify life, I was initially frustrated when I was told I could not use cells as a qualifying characteristic of living organisms. Afterall, years of research and hours spent looking at animals and plants under the microscope clearly showed that this is a characteristic of living things. The problem with it is that it is not a directly observable characteristic. Still, it is an accepted truth. Why can't I use it?

Then I realized that when applied to life beyond Earth, this characteristic might not hold true. Suppose life on Planet Farther doesn't even use DNA or similar, Earth-like cell structures. Plants aren't even guaranteed to be green. How would we know that these were plants? A definition of life based on what we observe with the naked human eye gives us the flexibility we need to understand new observations in different settings.


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