William Morse wrote:

> "Anon."  wrote in
> news:c4k5f7$vfg$1{at}darwin.ediacara.org: 
> 
> 
>>William Morse wrote:
>>
>>
>>>"Anon."  wrote in
>>>news:c4eskb$2adq$1{at}darwin.ediacara.org: 
>>>
>>>
>>>
>>>>William Morse wrote:
>>>
>>>
>>> (snip)
>>>
>>>
>>>
>>>>>With regard to kin selection, a weakness of Hamilton's rule is in
>>>>>getting an altruism gene established in the first
place. If the gene
>>>>>isn't at least locally widespread, the r factor will in
fact be low.
>>>>>For the flip side - the inability for a selfish gene to
spread - the
>>>>>reverse is true, since the more a selfish gene spreads,
the greater
>>>>>the selection pressure will be against it. 
>>>
>>>  
>>>
>>>
>>>>This is true for the first generation, after that it depends on
>>>>either the ability to recognise kin, or aggregation of kin.
>>>
>>>
>>>To clarify - are you referring to kin selection, anti-selfishness 
>>>selection, or both?
>>>
>>
>>Both - the problem is simply that the gene has to help other copies of
>>itself, which means there have to be multiple copies.
>>
> 
> 
> Right, but the flip side is that there _won't_ be multiple copies,
> because the selfish behavior will hinder other copies of itself. 
> 
And therein lies the problem.

For parental care, of course, this isn't a problem (as the behaviour is 
only expressed when there are multiple copies).  For other behaviours, 
the best I can do is plead the stochasticity of founder effects.  The 
overall effect is to reduce the rate at which altruistic behaviours 
evolve, and no doubt will stop it in some circumstances.

> 
> 
>>>>Of course, for behaviour like parental care, the problems are
>>>>reduced. 
> 
> 
>  
> 
>>>The above is the statement that made me think you are referring to
>>>kin selection.
> 
>  
> 
>>I was using it as it's the clearest example where the
"start-up cost"
>>is lowered.
> 
> 
>  
> Or in the case of the "flip side", the start-up barrier is
increased. If
> I have a gene that leads me to  obsessively hoard every nut I can find
> in excess of my needs, so that even my children can't find them, the
> gene won't spread even though the  behavior is beneficial to the
> individual. 
> 
Unless that means that you live much longer, and hence have sufficiently 
more offspring to offset the cost of the increased risk of starvation!

Bob

-- 
Bob O'Hara
Department of Mathematics and Statistics
P.O. Box 4 (Yliopistonkatu 5)
FIN-00014 University of Helsinki
Finland
Telephone: +358-9-191 23743
Mobile: +358 50 599 0540
Fax:  +358-9-191 22 779
WWW:  http://www.RNI.Helsinki.FI/~boh/
Journal of Negative Results - EEB: www.jnr-eeb.org
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