05-27-2012, 01:30 AM
Found another definition of Polarity.
http://users.iab.uaf.edu/~derek_sikes/zo...75-14a.pdf
This is a description I had not thought of, but it does seem to plug in nicely.
http://users.iab.uaf.edu/~derek_sikes/zo...75-14a.pdf
Quote:Introduction to Biosystematics
Why does polarity matter?
Direction of evolution: Polarity
• apomorphy: derived trait
• plesiomorphy: ancestral trait
This is a description I had not thought of, but it does seem to plug in nicely.

![[+]](https://www.bring4th.org/forums/images/collapse_collapsed.png)