Text 234, 176 rader
Skriven 2004-09-29 16:43:00 av Anon. (1:278/230)
Ärende: Re: Testing Evolution Via
=================================


John Edser wrote:

>>>>>>>>TT:-
>>>>>>>>It acts to cause undirected -
>>>>>>>>and most likely in the long term deleterious - changes in
>>>>>>>>the population.
> 
> 
>>>>>>>JE:-
>>>>>>>Therefore, I  see no _rational_ argument that
>>>>>>>can allow drift, which can only "cause undirected -
>>>>>>>and most likely in the long term deleterious -
>>>>>>>changes in the population" to cause evolution, yet
>>>>>>>this remains the Neo Darwinistic position in 2004.
> 
> 
>>>>>>TT:-
>>>>>>That's a simple matter of definitions:
>>>>>>Evolution is normally *defined* to be genetic change
>>>>>>in a population.
>>>>>>*Even* deleterious changes fit into that definition.
>>
>>>>>JE:-
>>>>>Drift is just a defined random
>>>>>process of sampling error.
>>>>>All random processes remain ubiquitous.
>>>>>Therefore, if you define any gene freq.
>>>>>changes via genetic drift as "evolution"
>>>>>and not as strictly "temporal variation" the
>>>>>theory of evolution becomes a non refutable.
> 
> 
>>>>BOH:-
>>>>This is wrong.
> 
> 
>>>JE:-
>>>Dr O'Hara has never understood the experiment
>>>I have proposed (please refer to Dr O'Hara's
>>>entirely confused rely).
> 
> 
>>BOH:-
>>It is not clear to Dr. O'Hara which "confused reply" is being referred to.
> 
> 
> JE:-
> Here is a copy of my reply to Dr O'Hara's entirely "confused reply":
> --------------------- copy ------------------------------------
> 
> 
>>>JE:-
>>>...
>>>I have described an experiment that can eliminate all
>>>natural selection within an _expanding_ population
>>>only allowing genetic drift as causative to allele
>>>freq. changes. All you have to do is artificially
>>>force all members of one population to raise the
>>>exactly the same number of fertile forms to adulthood
>>>where this number is larger than just a parental
>>>replacement value.  The prediction is: all natural
>>>selection must be halted within this experiment while
>>>Darwinian fitness equality can remain enforced. Thus only
>>>genetic drift (which cannot be eliminated) is now left
>>>to cause "evolution".
> 
> 
>>BOH:-
>>No, you've deleted drift as well.  The only way drift can be
>>re-introduced is for there to be genetic variation within a family
>>(through segregation), but in this case you can no longer guanrantee
>>"Darwinian fitness equality".  In other words, this doesn't allow you to
>>have your cake and eat it.
>>If you want to eliminate drift, then you need an infinite [effective]
>>population size.
> 
> 
> JE:-
> Dr O'Hara's reply seems to be completely
> confused. At the start Dr O'Hara
> comments: "you've deleted drift as well"
> when such an event is just experimentally
> impossible.  This is because (via BOH's own
> conclusion) "if you want to eliminate drift,
> then you need an infinite [effective]
> population size" which is an impossibility.
> 
That was not a conclusion: it does not follow from the preceding 
paragraph.  It was a statement, or a recommendation.

> I never suggested an intention
> to delete genetic drift simply because
> I could not do so even if I wanted
> to. 

But, alas, your experiment _does_ delete drift, as I have explained.

This is unless you are using a different meaning of the term " genetic 
drift", in which case I'd appreciate it if you acknowledge this, so that 
no one is confused by you terminology.

> 
>><snip>
>>
>>>>BOH:-
>>>>Here are a few actual examples in the literature where
>>>>people have actually used real data to test whether evolurion could be
>>>>due to drift:
>>>>Fisher, R. A., Ford. E.B., (1947). The spread of a gene in natural
>>>>conditions in a colony of the moth Panaxia dominula L. Heredity
>>
>>1:143-174.
>>
>>>>Koskinen M.T., Haugen, T.O., Primmer, C.R. (2002).  Contemporary
>>>>fisherian life-history evolution in small salmonid populations.  Nature
>>>>419: 826-830.
>>>>Manly, B.F.J. (1985).  The Statistics of Natural Selection.  Chapman &
>>>>Hall, London, U.K.
>>>>Mueller, L. D., Wilcox, B. A. , Ehrlich, P. R. , Heckel, D. G. , Murphy,
>>>>D. D. . 1985. A direct assessment of the role of genetic drift in
>>>>determining allele frequency variation in populations of Euphydryas
>>>>editha. Genetics 110: 495-511.
>>>>I've thrown in Manly because he has a re-analysis of the Fisher & Ford
>>>>data, as well as several other tests.  BTW, this list is not complete,
>>>>only a few choice picks from a manuscript of mine.
> 
> 
>>>JE:-
>>>Dr O'Hara has failed to understand the
>>>point of this discussion : TO PROVIDE
>>>POPPERIAN POINTS OF REFUTATION for the
>>>proposed evolutionary process of
>>>drift acting without selection.
> 
> 
>>BOH:-
>>Dr. O'Hara has provided references to tests of precisely the hypotheses
>>suggested, which indeed do provide refutations of the hypothesis that
>>the changes in the populations studied were due to genetic drift.  He
>>would advise Mr. Edser to read these references before commenting further.
> 
<snip another insult>
> 
> ________________________________________
> Please provide just one reference
> to a point of refutation that exists
> within the above for the hypothesis:
> "drift can cause evolution without
> selection".

All of them are references.  Try reading them - that's why I posated 
them.  Nature, at least, should be available from a decent library.

Bob

-- 
Bob O'Hara
Department of Mathematics and Statistics
P.O. Box 68 (Gustaf Hällströmin katu 2b)
FIN-00014 University of Helsinki
Finland

Telephone: +358-9-191 51479
Mobile: +358 50 599 0540
Fax:  +358-9-191 51400
WWW:  http://www.RNI.Helsinki.FI/~boh/
Journal of Negative Results - EEB: www.jnr-eeb.org
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