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Re: Mice given bat-like forelimbs through gene switch

----- Original Message ----- From: "Jura" <pristichampsus@yahoo.com>
Sent: Monday, January 21, 2008 10:59 AM

Not to be rude, but that is codwallop. An organism
is typically any free living, and occasionally not, cell or group
of cells that is coherently organised and has both metabolic
and reproductive functions. Viruses? Happy to say they are not
organisms, but *any* cell that functions singly is an organism.

What you are describing is life. Life forms and organisms are not one and the same (despite the prevalence of its use for everything including viruses). The latter is a "higher" level of organization of the former.

I have never come across a textbook or a biology teacher that implicitly or explicitly treated "single-celled organism" as a contradiction in terms. I'm used to "organism" being a synonym -- the jargon version, basically -- of "living being".

Sure, most multicellular organisms do consist of organs that consist of tissues* that consist of cells. This is indeed taught everywhere. But I've never seen it implied that this hierarchy is the _definition_ of "organism". It just happens to be the case that most multicellular organisms don't directly consist of unorganized cells, and this important fact is taught early on.

"Creature" is not an option outside English, and even there you wouldn't normally apply it to plants, would you?

* Hm. Actually... I suppose you could get away with calling blood and lymph "organs", but blood cells certainly aren't a tissue! Sponges, on the other hand, have tissues, but do they have organs?