Re: Discussion on GM and phylogeny

[morphmet_moderator]

----- Forwarded message from Aki Watanabe <awatan...@amnh.org> -----

Date: Sun, 24 Nov 2013 10:15:24 -0500
From: Aki Watanabe <awatan...@amnh.org>
Reply-To: Aki Watanabe <awatan...@amnh.org>
Subject: Re: Discussion on GM and phylogeny
To: "morphmet@morphometrics.org" <morphmet@morphometrics.org>

Dear Shobnob,

Geometric morphometrics can be incorporated as characters in a phylogenetic analysis (see Goloboff and Catalano papers in the journal Cladistics for parsimony analysis of aligned GM data), but I don't think it has been implemented in maximum likelihood or Bayesian analysis before perhaps because choosing probabilistic and prior distribution models for evolution of landmark data is a tricky issue. 

That said, I personally prefer NOT to use GM data as phylogenetic data because of few reasons: (1) phylogenetic characters need to be independent of each other, but landmarks that are close together will likely not be independent; (2) it is suspicious that individual landmarks appropriate evolutionary units, especially whether "geometrically or functionally" homologous landmarks are "evolutionarily" homologous; and (3) if x, y, (and z) coordinates of each landmark are taken as separate characters, then the result will be dependent on the orientation of the specimens after alignment (Goloboff and Catalano's method treats each landmark as character so this problem doesn't apply to their method). 

There may be more arguments, but these are my primary reasons against using GM data as phylogenetic characters. 

All the best,

Aki

On Sunday, November 24, 2013, wrote:

----- Forwarded message from Shobnom ferdous <sfdeeb...@yahoo.com> -----

Date: Sun, 17 Nov 2013 11:57:35 -0500
From: Shobnom ferdous <sfdeeb...@yahoo.com>
Reply-To: Shobnom ferdous <sfdeeb...@yahoo.com>
Subject: Discussion on GM and phylogeny
To: "morphmet@morphometrics.org" <morphmet@morphometrics.org>

Dear Friends

I would like to get some discussion or opinion on the following matter:

Why we cant incorporate  a morphological phylogeny or Geometric morphometrics analysis, Molecular phylogeny all together to get a phylogeny for a particular group, rather we use a molecular phylogeny and overlay that with GM work? I have read the related papers but some discussion is much appreciated. 

Sincerely,

Shobnom

Reply to:

sfdeeb...@yahoo.com

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