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  Topic: UnReasonable Kansans thread, AKA "For the kids"< Next Oldest | Next Newest >  
Tom Ames



Posts: 238
Joined: Dec. 2002

(Permalink) Posted: Sep. 19 2008,21:58   

Quote (Ftk @ Sep. 19 2008,16:53)
 
Quote
Most methods assume a non-reticulate tree (that is, they assume that there are no instances in which populations rejoin and species merge).


Can you elaborate on that paragraph a bit?  I'm not sure I'm getting what you're saying.

A bifurcating tree might look like this (pardon the cruddy figures):
Code Sample

\     /   \    /    /
\   /     \  /   /
 \ /       \/  /         ^
  \        /  /           |
    \    /  /           time
     \ /  /
      \  /            


A reticulated tree simply allows reconnections between branches:
Code Sample

\     /    / /
\   /\   / /
 \ /   \/ /
   \   / /
     \/ /
      \/


The second tree might exemplify two populations merging again after a split. The technical term, "reticulate" or "reticulated" is from the latin word for net. (The tree is netlike rather than strictly bifurcating, or splitting.)

BTW, do you agree that I answered your question "What is the material benefit of a discovery in physical anthropology?"

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-Tom Ames

  
  10202 replies since Mar. 17 2007,23:38 < Next Oldest | Next Newest >  

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