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Re: primers




"Jaime A. Headden" wrote:
> 
> John Hunt (john.bass@ntlworld.com) wrote:
> 
> <I think I can see why cladistics and traditional systematics have a
> problem.  I recent thread made reference to dogs and I believe all
> domestic dogs are considered to be the same species as they can
> interbreed.  Would a cladistic analysis of domestic dogs make Great Danes
> and Jack Russels monophylitic?>
> 
>   Certainly, several studies have sponsored a monophyletic relationship
> between all domestic canines, and a sister-group relationship with wolves
> (Canis spp.) in which it is offered that wolves and dogs are subspecies of
> a single species (Canis lupus subspp.) which are then further divided by
> varieties and races, then breeds. Other, more recent studies, show that
> modern dog diversity has arisen from several domestication events from
> similar "wolf" species, suggesting that instead of a single speciation act
> (brought on by domestication), there may have been upwards of three, or
> more. These analyses were all wrought cladistically, using various DNA and
> mtDNA sequences.

I think the real question was; if dogs were only known from fossil
remains, and DNA (nor interbreeding evidence) wasn't available, would
their range of variation still lend then to be recognised as a single
species? Or would the fact that skeletal structure is only a tiny part
of the variation of a species (and can be altered by relatively minor
genetic changes) mean that cladistics would produce an over-simplistic
view of relationships?

-- 
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Dann Pigdon
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://heretichides.ravencommunity.net/
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