More on the 'cladistics' of sequences

[Richard Jensen]

Richard,

"Well, not really" what.  Of course morphological data can be used the same way
as molecular data.  My point to John was that morphological data are no more
likely to yield a "correct" phylogeny than are any other type of data.  And, as
we all know, we can never know if we have the "correct" phylogeny or not.
Lamboy's simulations documented that even when the correct phylogeny is known,
maximum parsimony of the kinds of data matrices that most systematists generate,
is not very accurate (his word).

Cheers,

Dick

Richard.Zander at MOBOT.ORG wrote:

> Well, not really. Morphological data can be used in the same way as
> molecular data to come up with testable, well supported hypotheses. Proof is
> that morphological results generally duplicate molecular results. See my:
> http://www.phyloinformatics.org/pdf/2.pdf paper for how to estimate
> confidence intervals for morphologically based cladogram internodes.
>
> Accuracy is of course the big bugaboo but is a problem for molecular data,
> too.
>
> -----Original Message-----
> From: Richard Jensen [mailto:rjensen at SAINTMARYS.EDU]
> Sent: Tuesday, June 08, 2004 7:23 AM
> To: TAXACOM at LISTSERV.NHM.KU.EDU
> Subject: Re: [TAXACOM] More on the 'cladistics' of sequences
>
> Morphological data are especially difficult to
> evaluate and, in fact, are unlikely to provide "accurate" phylogenies (see
> Lamboy, 1994. Systematic Botany 19: 489-505). Yes, Lamboy's analyses were
> based on simulated data, but the data matrices generated were not unlike
> real morphological data matrices.
>
> ______________________
> Richard H. Zander
> Bryology Group
> Missouri Botanical Garden
> PO Box 299
> St. Louis, MO 63166-0299
> richard.zander at mobot.org <mailto:richard.zander at mobot.org>
> Voice: 314-577-5180
> Fax: 314-577-9595
> Websites
> Bryophyte Volumes of Flora of North America:
> http://ridgwaydb.mobot.org/bfna/bfnamenu.htm
> Res Botanica:
> http://ridgwaydb.mobot.org/resbot/index.htm
> Shipping address for UPS, etc.:
> Missouri Botanical Garden
> 4344 Shaw Blvd.
> St. Louis, MO 63110

--
Richard J. Jensen              | tel: 574-284-4674
Department of Biology      | fax: 574-284-4716
Saint Mary's College         | e-mail: rjensen at saintmarys.edu
Notre Dame, IN 46556    | http://www.saintmarys.edu/~rjensen