return to main index

  mobile - desktop
follow us on facebook follow us on twitter follow us on YouTube link to us on LinkedIn
International Reptile Conservation Foundation  
click here for Rodent Pro
Mice, Rats, Rabbits, Chicks, Quail
Available Now at RodentPro.com!
Locate a business by name: click to list your business
search the classifieds. buy an account
events by zip code list an event
Search the forums             Search in:
News & Events: Herp Photo of the Day: Rainbow Boa . . . . . . . . . .  Herp Photo of the Day: Gecko . . . . . . . . . .  Southwestern Herp Society Meeting - Feb 01, 2025 . . . . . . . . . .  Greater Cincinnati Herp Society Meeting - Feb 05, 2025 . . . . . . . . . .  Calusa Herp Society Meeting - Feb 06, 2025 . . . . . . . . . .  St. Louis Herpetological Society - Feb 09, 2025 . . . . . . . . . .  Kentucky Reptile Expo - Feb. 15, 2025 . . . . . . . . . .  Colorado Herp Society Meeting - Feb 15, 2025 . . . . . . . . . .  Chicago Herpetological Society Meeting - Feb 16, 2025 . . . . . . . . . .  San Diego Herp Society Meeting - Feb 18, 2025 . . . . . . . . . .  Suncoast Herp Society Meeting - Feb 22, 2025 . . . . . . . . . .  DFW Herp Society Meeting - Feb 22, 2025 . . . . . . . . . . 
Join USARK - Fight for your rights!
full banner - advertise here .50¢/1000 views
Click here for Predator Foods
pool banner - $50 year

RE: Polyphyletic

[ Login ] [ User Prefs ] [ Search Forums ] [ Back to Main Page ] [ Back to Taxonomy Discussion ] [ Reply To This Message ]
[ Register to Post ]

Posted by: emoneill at Wed Oct 1 15:41:43 2008  [ Report Abuse ] [ Email Message ] [ Show All Posts by emoneill ]  
   

I assume you mean ectothermy rather than endothermy and symplesiomorphies instead of synaplesiomorphies. If so, then you are on the right track. Personally I can't figure out why anyone would want to recognize either para or polyphyletic taxa. Neither reflects phylogeny, and I find that taxonomy based on phylogeny is the most informative. Cking seems to think there is something "natural" about paraphyletic taxa, but I don't see it.

Here is an example of what can happen when you consider paraphyletic groups to be valid taxa. Let's say there are 4 species in genus X, and each member of the genus possesses some autapomorphy in a different character (while the other species are plesiomorphic). Let's use an example based on DNA for simplicity.

For gene X:
Position 10: species A has the nucleotide T
Position 11: species B has the nucleotide A
position 12 species C has the nucleotide G
position 13 species D has the nucleotide C

Let's assume the real relationships among the species are (A,B)(C,D). We could exclude any of the species from the group by their autapomorphy, just like birds are excluded from reptiles for their autapomorphies. So what is the "best" paraphyletic taxonomic grouping based on plesiomorphies.

A,B,C as one taxon?
How about A,C,D?
Maybe A,B,D?

I see no objective answer. If I asked you to name every monophyletic group, anyone who understands the definition of monophyly can do that. So besides the fact that peraphyletic goups do not reflect phylogeny, they can also be quite arbitrary.

What is the point?


   

[ Reply To This Message ] [ Subscribe to this Thread ] [ Show Entire Thread ]


>> Next Message:  RE: Polyphyletic - apeltes, Wed Oct 1 21:38:14 2008

<< Previous Message:  RE: Polyphyletic - apeltes, Wed Oct 1 12:22:03 2008