John Edser wrote:
>>>>BOH:-
>>>>The means of quantifying "all evolutionary
change" here is not clear.
>>>>State the metric used - and the question of whether genetic drift
>>>>comes in at the #1 position will probably be clearer.
>>>
> 
>>>LM:-
>>>I mean the sum all evolutionary changes of any sort by whatever 
>>>definitions are used by a large number of scientists.
>>
>  
> 
>>>JE:-
>>>Pardon me butting in but..
>>>please state what would be EXCLUDED from such an
>>>_amazingly_ wide acceptance of what you insist can
>>>_scientifically_ constitute "evolution", i.e. please 
>>>provide at least one example of a _non_ evolutionary 
>>>change within a biological system.
>>
> 
> BOH:-
> Any change that isn't heritable.
> 
> JE:-
> The above becomes a self fulfilling prophecy 
> when genetic epistasis is _defined_ as "inherited"
> but not "heritable" and thus, "selectable". 

Huh?  From the OED definition of heritable: Naturally transmissible or 
transmitted from parent to offspring; hereditary.

You're mixing up being heritable with the qunatitative genetic concept 
of "heritability" (=the proportion of variance in a trait due to 
additive genetic variation).  They are not the same thing.

>>>LM:-
>>>Did you have something else in mind that would 
>>>shift random genetic drift into second place?
>>
> 
>>>JE:-
>>>Darwinian natural selection, exactly as Darwin
>>>stated it but with his implicit assumptions
>>>made explicit.
>>
>  
> 
>>BOH:-
>>I think I should point out that John's definition of fitness excludes 
>>the possibility of drift (because he defines fitness in terms of the 
>>actual number of offspring, rather than the expected value).
> 
>  
> 
>>JE:-
>>Dr O'Hara has misrepresented my position.
>>Drift is _included_ as temporal variation
>>(random variation over time) within Darwinian
>>selective events. 
> 
> 
> BOH:-
> John, what is your definition of fitness?  I was specifically describing 
> your definition of fitness, but in your reply you didn't make any 
> mention of it, so it's not clear to me how I've misrepresented you.
> 
> JE:-
> It is not how I define it but how Darwin
> would have defined it after his implicit
> assumptions were made explicit.
> 
> I have posted what Darwinian fitness is (and the
> reverse engineering experiment needed to prove it)
> countless times, including, within this thread. 
> 
> _____________________________________________________
> Darwinian fitness is the _total_ number of _fertile_
> forms reproduced by _one_ Darwinian selectee
> (one fertile form) within _one_ population. 
> _____________________________________________________
> 
OK, so my point is that drift is the difference between observed and 
[mathematical] expectation of the change in allele frequency (the 
expectation coming from a model of selection, using the conventioal 
definition of fitness): the total number of fertile offspring is the sum 
of the expected number, and the drift effect.  Your definition conflates 
the effects of selection and drift, by defining fitness in terms of the 
obseved number.  Any random variation in the number of offspring that we 
  would ascribe to drift you would include in the fitness measure, and 
hence would ascribe to selection.

Bob

-- 
Bob O'Hara

Dept. 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: http://www.jnr-eeb.org
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 6/8/04 12:23:31 PM