RE: Mice given bat-like forelimbs through gene switch

[Tim Williams <twilliams_alpha@hotmail.com>]

David Marjanovic wrote:


> Neither phenetics nor cladistics are limited to morphology. This is the
> first time I come across someone believing that they are.


True, DNA-DNA hybridization techniques (for example) were a type of phenetics.  
But nobody uses this technique in molecular analyses.  Not any more, anyway.  
AFAIK, the only application for phenetics these days is in morphological 
comparisons.  I've heard botanists still do it (though don't ask me for 
details).


As to whether molecular phylogenetic analyses qualify as "cladistic", I've 
heard differing points of view.  I tend to limit the term "cladistic" to those 
analyses that use a parsimony-based approach (as morphology-based analyses do). 
 But most molecular phylogenetic analyses tend to use statistics-based 
evolutionary models to analyze sequence data (e.g., maximum likelihood, 
Bayesian inference) rather than a parsimony-based approach.  I don't want to 
get bogged down into a debate over whether Hennig came up with the concept of 
parsimony for assessing evolutionary relationships; but in any case the fact 
remains parsimony has become the foundation for cladistic analysis, and other 
approaches (e.g., maximum likelihood, Bayesian inference) are regarded as 
"non-Hennigian".


>> To be honest, I don't know to what extent PhyloCode could (or does
>> already) apply to the classification of bacteria and archaea.
>
> It allows you to name clades and define those names... just like elsewhere.


Fair enough.  It's just yet to become standard for prokaryotic taxa.


Cheers

Tim

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