Posted by:
ScottThomson
at Mon Mar 8 17:18:32 2004 [ Report Abuse ] [ Email Message ] [ Show All Posts by ScottThomson ]
I do not think the concept that "true" phylogeny is recoverable has been falsified. There is too much unknown throughout the phylogenetic history.
I had this argument recently where someone was uncomfortable with a genus because it was monotypic, yet it actually had three described species. The point is that the geneticist in question failed to know that the taxa he worked on had two described species he was unaware of. How is this possible, well they were both fossils. But that does not mean they did not exist.
So of course this means that as fossil history is only partially recoverable, at best, the so called "true" phylogeny is not going to be recoverable. Of course a phylogeny based only only on living forms is so full of gaps it is not a "true" tree either.
The second difficulty is the isssue that many of the attempts to claim the "true" tree are based on molecular evidence which has only 4 states for each character and the most parsimonious view is that any of these states is equally probable (not entirely true I know, I am just making a point). Hence the overwriting and rewriting of the genetic characters would have to be taken as a given probability. So again the so called "true" tree is masked.
Personally I think phenetics has its uses, its a good tool for testing and developing field keys. Thats a good use and necessary and worthwhile. I am not going to develop trees with it though as its incapable of recognising homoplasy.
Cheers, Scott Carettochelys.com
----- Scott Thomson
If you believe you can or you can't you are always right.
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