ON OUTGROUPS

@article{Nixon1993ONO,
  title={ON OUTGROUPS},
  author={Kevin C Nixon and James M. Carpenter},
  journal={Cladistics},
  year={1993},
  volume={9}
}
Abstract— The relations among polarity, outgroups and rooting are clarified. The “outgroup algorithm” and “outgroup substitution method” are irrelevant forms of relaxed parsimony. They should be discarded in favor of unconstrained, simultaneous analysis of all terminals. A revised outgroup method is described both in text and with a computer‐generated flowchart. Lundberg rooting is consistent with cladistic parsimony only under specific circumstances involving hypothetical ancestors. 
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