Definition of life

[Richard Streng t2997]

Attila Pusztai wrote:

>What about circulating red blood cells, without nucleus? Aren't they alive?

Red blood cells of mammalia without a nucleus aren't alive in the
sense of my definition. Such a cell is merely a part of a living
system which is still able to fulfill some functions for a limited
time period.

Hubert Martin Sauro in this newsgroup actually gave a similar
definition.

Generally we have to discriminate between two sights by a definition
of life.
1. We mean a complete organism (with its ability to reproduce), or
2. we mean any part of the organism downto a single cell of it.

I think that some assimilation processes within cells which have a more 
or less diminuated genetic information (as in a lot of somatic cells)
are not sufficient to define life. A definition of live should have
in mind that only by reproduction any evolution can occur.

Well, if one asks me whether a freshly plucked flower is alive or
not, I would like to say yes. But the answer is in that second mode of 
view.

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Richard Streng
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