Jim Menegay wrote:

> "Anon."  wrote
in message news:...
> 
>>Jim Menegay wrote:
>>
>>>August West  wrote in message
news:...
>>>
>>>
>>>
>>>>[Snip some good and wise stuff]
>>>>Yes, I was saying that Hamilton's rule is a mathematical relationship
>>>>that in itself is not subject to testing (provided, of
course, that it
>>>>is internally consistent). I would say the same for natural
selection,
>>>>except that it is more pure logic than mathematics. 
>>>>[Snip more good and wise stuff]
>>>
>>>
>>>I agree with everything said in this post and (despite my apparent
>>>complaint) in its predecesor.
>>>
>>>But, to sharpen the focus a little on the epistemology - some comments
>>>and a question.
>>>
>>>Consider the somewhat vague hypothesis "Genes that promote the 
>>>fitness of the organisms that contain them will proliferate".
>>>
>>>This hypothesis certainly SEEMS to be testable - it is not pure
>>>mathematics.  But there are problems when we try to clarify the
>>>meaning of the key words "fitness" and "proliferate".
>>>
>>>One possible issue with fitness is the old canard about "Natural
>>>Selection is a tautology."  Ignore this - I don't want to go into
>>>this issue.
>>>
>>
>>I think you might end up there anyway!  I'll just point out that fitness 
>>is defined to be specific to the environment, so if the environment 
>>changes, so might fitness.
> 
> 
> My "ploy" to avoid being dragged into this issue is to claim
that there
> is a distinction to be made between "fitness" and
"reproductive success",
> and that fitness is the cause of reproductive success.  I then shut
> my mind to those who point out that there is no other way to measure 
> or estimate fitness than by measuring reproductive success.
> 
> This ploy may be epistemologically naive, but it works for me!
> 
I totally agree.  To me fitness is a mathematical expectation, and 
reproductive success what is observed.

Brandon wrote a nice discussion about this, except he buggered up the 
terms.  What he called fitness we would call reproductive success, nad 
what he called adaptiveness we would call fitness.


> 
> In your evaluation of my four variants, you seem to be saying that none
> of the four is exactly "wrong", but that there are technical
advantages
> in sticking with the traditional formulation - short term relative fitness.
> If you stick to the short term, you may assume a constant environment,
> and you avoid the mathematically messy operation of averaging fitnesses
> over a range of environments.  Furthermore, if you stick to relative
> fitnesses, you are choosing a variable that is (in principal) accessible
> experimentally, whereas absolute fitnesses are meaningful only in the
> non-realistic limit of an infinite carrying capacity.  
> 
> And, all that is well and good.  But, the thing is, the creationists
> caricature Natural Selection as being the kind of short-term population-
> genetics process that you describe it as, and assert (with some reason)
> that it can never lead to innovation, speciation, remarkable adaptation,
> and the other marvels that Darwin claimed.
> 
It's not clea to me that population genetics needs to worry too much 
about the creation of innovation - but once it's there, we can say 
what's going to happen to it.  The creation of innovation is something 
for the evo-devo people or palaeontologists to deal with.

> Furthermore, it somehow seems wrong that Hamilton would extend Fisher
> to deal with "social" phenomena, but then reinforce the hypothesis
> that fitness is density-independent.  It seems particularly wrong since
> "b" is to be calculated by summing over the population.
> 
Yes, but for most individuals in most applications, b will be zero.  An 
individual won't go round trying to help all 56234 members of the 
population, but only some of those that it meets.

Bob

-- 
Bob O'Hara

Rolf Nevanlinna Institute
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/
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