[Taxacom] Molecular data and synapomorphies
Richard Zander
Richard.Zander at mobot.org
Wed Dec 3 16:04:25 CST 2008
Alan Forrest wrote:
"Further, from Richard Zander's comments, it is clear that there still exists an unproductive split in opinion between molecular systematists and their more 'traditional' counterparts. It is reminiscent of phenetics vs. cladists, horticulture vs. science depts in botanic gardens, barcoding vs. the loss of field systematic expertise etc etc."
My comment:
Yes, and only recently has there been much of an outcry. Like the cow in the Larson cartoon: "Hey! This is grass. We've been eating grass!" The only way one can deal with this split is to offer a third way, a combined method to produce a better product.
Total evidence is not that, since we are combining in one analysis molecular data on genetic continuity with morphological data from studies searching out conservative probably selectively linked traits. Combining apples and orangs give cole slaw.
I (and Jimmy Carter and the Dahlia Lama) recommend my syncretic method as a possible third way:
http://tinyurl.com/6frd9l
:)
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander at mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
-----Original Message-----
From: Alan DAvid Forrest [mailto:aforrest at rjb.csic.es]
Sent: Wednesday, December 03, 2008 12:56 AM
To: John Grehan
Cc: Richard Zander; taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Molecular data and synapomorphies
It is nice when this discussion group generates compatibility and
usefulinformation exchange!
FASTA format, to me, was near universal - therefore it is good to
discover that this is not the case. I have modified my viewpoint
accordingly. I find NEXUS over complex and also have to resort to online
conversion software, some of which is not very good.
Further, from Richard Zander's comments, it is clear that there still
exists an unproductive split in opinion between molecular systematists
and their more 'traditional' counterparts. It is reminiscent of
phenetics vs.cladists, horticulture vs. science depts in botanic
gardens, barcoding vs. the loss of field systematic expertiseetc etc.
Perhaps the most enlightened are those who prefer to take a
multidisiplinary and co-operative approach. As such, it would be nice to
see funding proposal success based on this. I note the comment about a
lack of funding for morphological taxonomy - although in the UK (my home
base) it is also very difficult to obtain funding for molecular
systematics as well (unless you have a permanent position and access to
institutional labs).
The lack of standards and their rigorous enforcement seems to be an
issue that needs addressing in all disciplines.
Alan
John Grehan escribió:
>
>
>> -----Original Message-----
>> From: Alan DAvid Forrest [mailto:aforrest at rjb.csic.es]
>>
>
>
>
>> I personally stick to simple text or fasta alignments that can be used
>> virtually anywhere else without conversion.
>>
>
> As an ignorant non-molecular biologist I had never heard of this format
> until recently. Then I was not able to open some such files, even with
> software that was supposed to do that. I had to have a colleague convert
> to nexus and also direct me to some web programs before I could do
> anything. I came across a website that was designed as a repository for
> molecular data that would make access automatic, but not many were using
> at such.
>
> One key requirement is access to the alignments as they were aligned by
> the original authors since different alignment programs may give
> different results. In at least one case the data was not in its aligned
> format.
>
> Another problem I have had is identifying EXACTLY how many sequences
> comprise each gene of each taxon compared. That might be easy for a
> molecular systematist to figure out, but not for me.
>
> I am not sufficiently
>
>> knowledgable about morphological, biogeographical or cytological data
>>
> to
>
>> comment on how such data is currently stored, but would be happy to
>> learn (suggestions welcome).
>>
>
> At least with morphological data, one would expect accurate descriptions
> and illustrations for each taxon for a particular character, or at the
> very least citations to sources with such information. Unfortunately
> that seems to be wanting in many morphological studies (so a counterpart
> to access to molecular data) - particularly for larger groups. All too
> many systematists just make proclamations about characters and
> concentrate on generating 'lots' of them as if this will somehow snow
> everyone on the lack of actual documentation. I've seen this in the
> human origins field where various studies get acclaim for their many
> characters without any attention to the fact that most don't even have
> comparative illustration of their veracity. Other characters continue to
> be recycled even when they have been shown to be incorrect.
>
>
>> As for 'more informed interpretation' I mean simply: how can one
>>
> decide
>
>> if a particular type of data is 'best' or 'correct' without comparison
>> to other data?
>>
>
> Ok.
>
> John Grehan
>
>
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