On 1/14/2011 2:27 AM, Invisible wrote:
>>> I think we need to distinguish between DNA that isn't used for anything,
>>> and DNA which actually produces proteins, but they don't do anything
>>> really useful.
>>>
>>> Just having a sequence in your genome doesn't really cost that much.
>>> Synthesizing it into a protein is much more expensive.
>>>
>>> It wouldn't surprise me if non-eukaryotes have fewer genes turned on,
>>> and possibly smaller genomes, but I doubt that they have radically
>>> "cleaner" genomes.
>
>> You are forgetting that you *still* have to copy all that extra stuff,
>> when ever you divide the cell, so there is still a cost to synthesize
>> all the copies, before the cell splits to form new cells.
>
> Yes, there is a cost. What I'm saying is that it's a very small cost.
>
>> Also, its not
>> a simple case of, "just ignore the stuff I don't use", something has to
>> run through the pattern, decide what needs to be unfolded, or folded,
>> jump past any stuff that is folded into an unusable state, etc.
>
> It's not like a computer, doing a linear scan of the entire genome
> looking for active genes. It doesn't work like that.
>
> As far as I know (and I'm not an expert on the subject), having extra
> inactive genes imposes very little penalty for transcription.
>
>> And, most of the code, unlike in multi-celled organisms, is going to be
>> "on". There is no reason to turn parts off, except for mitosis, and the
>> like, if you are not differentiating the cells
>
> False.
>
> Unicellular organisms might not build colonies of differentiated cells,
> but that does *not* mean that all genes are switched on, all the time.
>
> There are organisms that can metabolise both aerobically and
> anaerobically. That's two different metabolic pathways, involving
> different sets of proteins. Many if not most organisms can utilise more
> then one food source. That's different sets of proteins. Many organisms
> have a life-cycle more complex them just "grow, divide, grow, divide".
> That requires different sets of proteins. Some cells even signal each
> other, and undergo limited differentiation under certain conditions.
> More sets of genes. Then there are genes only used in response to attack
> or damage. And so forth.
>
> Seriously. Few if any organisms go around with *all* their genes
> switched on all the time.
Well.. Ok, saying "all" may have been a bit inaccurate. What I meant is 
you don't generally see, with a few exceptions, entire sets of genes 
"off" all the time, once they have been used, such as developmental 
precursors, etc. In any case, you assumption of what the cost may be is 
precisely that, an assumption. My assumption is, based on the article I 
linked to, that the costs *must* be higher than you are assuming.

-- 
void main () {

     if version = "Vista" {
       call slow_by_half();
       call DRM_everything();
     }
     call functional_code();
   }
   else
     call crash_windows();
}

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