I imagine it's similar to how viruses are not considered to be alive, since they cannot reproduce without a host cell?
But I have never been a fan of that argument either, both seem alive to me.
But I have never been a fan of that argument either, both seem alive to me.
It's a bit like if you took the heart from an animal and transplanted it into a human: is it meaningful to call it independently alive? Maybe, it depends what question you're trying to ask.
The uncertainty, I understood, was whether to classify them as distinct organisms the way we classify other species, as they are intrinsically parasitic for their replicative capability.
In fact the only place they fit the definition is reproduction, and that is only through the machinery they commandeer from the cells they infect.
To me viruses clearly do not fit the definition of life. But fire... that is hard to exclude from the definition without some mental contortions. I am not advocating that fire is alive for any useful reason, but it is hard to exclude from the definition.