[Taxacom] 53 million year rabbit foot

John Grehan jgrehan at sciencebuff.org
Sun Nov 20 11:50:47 CST 2011


But the point is that unless there is anything in the fossil that shows it is basal, there is no necessity. But if the fossil can only be placed within a particular group, but no subgroup, then naturally it only provides the MINIMUM timing of the group to which the fossil is assigned.

John Grehan 

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Jason Mate
Sent: Sunday, November 20, 2011 8:59 AM
To: Taxacom
Subject: Re: [Taxacom] 53 million year rabbit foot


Apologies, I should have been more specific, i tend to think in extant taxa only. I meant basal to the crown, i.e. plesion or at least stem "group". As to why, if it looks like a "rabbit" but not any specific one or it is fragmentary, you can only say something about the timing of the crown node.

Best
Jason

An incertae sedis plesion, I would say.
Cristian


-----taxacom-bounces at mailman.nhm.ku.edu ha escrit: -----

Per a: Jason Mate <jfmate at hotmail.com>
De: Michael Heads <michael.heads at yahoo.com> Enviat per: taxacom-bounces at mailman.nhm.ku.edu
Data: 20/11/2011  10:56
a/c: "taxacom at mailman.nhm.ku.edu" <taxacom at mailman.nhm.ku.edu>
Assumpte: Re: [Taxacom] 53 million year rabbit foot

Yes, but why assume that a fossil must be basal in the phylogeny?
 
Michael

Wellington, New Zealand.


My papers on biogeography are at: http://tiny.cc/RiUE0 Information on my new book, 'Molecular panbiogeography of the tropics', is at: http://www.ucpress.edu/book.php?isbn=9780520271968



________________________________
 From: Jason Mate <jfmate at hotmail.com>
To: Taxacom <taxacom at mailman.nhm.ku.edu>
Sent: Sunday, 20 November 2011 10:38 PM
Subject: Re: [Taxacom] 53 million year rabbit foot
 

Hiya Michael/John
If you have a fossil and you can only be certain that it belongs to a particular group (Lagomorpha) but nothing more (is it a rabbit, a hare, Bugs Bunny,...?) then you only have a date for Lagomorpha, for the conceptual type, e.g. the whole group. In this way you make the least possible number of assumptions as the fossil only represents a date (53my) on a bunch of characters (= Lagomorphisness).
Jason

Date: Sat, 19 Nov 2011 01:54:11 -0800
From: michael.heads at yahoo.com
Subject: Re: [Taxacom] 53 million year rabbit foot
To: jfmate at hotmail.com
CC: taxacom at mailman.nhm.ku.edu

Hi Jason, Why is it parsimonious to assume that a fossil member of a group, but with an unknown position within the group, is basal in that group? Michael Wellington, New Zealand.

My papers on biogeography are at: http://tiny.cc/RiUE0
Information on my new book, 'Molecular panbiogeography of the tropics', is at: http://www.ucpress.edu/book.php?isbn=9780520271968

       From: Jason Mate <jfmate at hotmail.com>
To: Taxacom <taxacom at mailman.nhm.ku.edu> 
Sent: Saturday, 19 November 2011 8:53 PM
Subject: Re: [Taxacom] 53 million year rabbit foot
  

I think KenĀ“s point is that nodes on dated phylogenies come with an uncertainty range, and hopefully the authors of the dated phylogeny provided them. Saying 35my and 35my (-20my) are very different things, so it is hardly proof of a fatal flaw in the edifice on fossil calibrated molecular phylogenies. In any case, the more fossils the better the calibration. In regards to crown versus stem, I would point out that if the fossil looks like a rabbit but
you are uncertain about its exact placement, you assign it to all the rabbits (basal). It is not necessarily the best solution but it is the most parsimonius.
Jason
                          
_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of these methods:

(1) by visiting http://taxacom.markmail.org

(2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here


  
                            
_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of these methods:

(1) by visiting http://taxacom.markmail.org

(2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here
_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of these methods:

(1) by visiting http://taxacom.markmail.org

(2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here


 		 	   		  
_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of these methods:

(1) by visiting http://taxacom.markmail.org

(2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here




More information about the Taxacom mailing list