3.17.06 L65 - Lecture 65 Phylogenetic Trees and Phylogeny...

Info icon This preview shows pages 1–2. Sign up to view the full content.

March 17, 2006 Lecture 65: Phylogenetic Trees and Phylogeny Synaptomorphy – Shared Derived Character Parsimony – The principle of simplicity. (simplest way to get there) a.k.a. Occam’s Razor, KISS  principle (Keep It Simple Stupid) Ingroup  – Taxa of primary interest Outgroup  – Taxa that lie outside the group of interest and are the sister taxon to the ingroup.  Homoplasy  – Similarity due to independent evolutionary change (often mistaken for homology) Reconstructing Relationships Use shared-derived characters (synaptomorphies)   family tree of taxa Taxa sharing a derived character state are more closely related to each other that to  taxa  that have the ancestral character state.  Shared-derived characters at different levels in the tree can help us reconstruct the 
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: branching pattern throughout the tree • Remember: Any given Tress is considered to be a Hypothesis. Identifying Synaptomorphies • Synapomorphies help us reconstruct evolutionary relationships. Synapomorphies v. homoplasies: Two major ways of differentiating • Choose characters that appear to be homologies • Use many characters for phylogenies—reduce effect of a few homoplasies. Method of Phylogenetic Recostruction: • The Hypothetic creatures of Llenoc • Create character matrix • 4 changes • Construct the most Parsimonius Tree • Parsimonies usually accepted. What characters can be used to constryuct phylogeies? • morphological • molecular • behavioral Use of Phylogentics • Overlay, for example •...
View Full Document

  • Summer '07
  • GILBERT,C.
  • Cladistics, Phylogeny, Phylogenetics, Synapomorphies, Synaptomorphies · Synapomorphies, Derived Character Parsimony, independent evolutionary change

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern