BIOS
W1L2 Tree Thinking2.pdf

Trees a road map to terminology 57 clades clade not a

Info icon This preview shows pages 7–14. Sign up to view the full content.

Trees: a road map to terminology 57
Image of page 7

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

Clades Clade Not a Clade Clade = all the descendants of a common ancestor. Also called a monophyletic group 58 Groupings - Monophyletic groups (= clades) 59 Groupings - Paraphyletic groups ( clades) 60
Image of page 8
Paraphyletic taxonomy 61 The tree of life: paraphyletic prokaryotes & protists 62 The problem with paraphyly -- Classification of higher taxa should be based on common descent (monophyletic groups) -- Paraphyly misleads regarding relationships - Did you know birds are nested within reptiles? - How does this distort our perception of the evolution of parental care, vocalization, endothermy, and other traits? -- Why paraphyly persists? - Grades vs. Clades - Tradition -- Herpetology = the study of amphibians and reptiles - Institutionalized paraphyly! 63
Image of page 9

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

Monophyly, Paraphyly, Polyphyly Haemothermia = polyphyletic Reptilia = paraphyletic Tetrapoda = monophyletic 64 64 Monophyly, Paraphyly, Polyphyly Monophyletic group (= clade) : a group consisting of all the descendants of a common ancestor Paraphyletic group : an ancestor and some, but not all, of its descendants. Polyphyletic group : A group that is not united by a common ancestor that is a member of that taxon (i.e., the common ancestor is placed in another higher taxon). This is always a mistake, and the features used to define such groups are usually convergently evolved. 65 Groupings } } } Sister Taxa Sister Taxa Sister Taxa 66
Image of page 10
Groupings } } Sister Clades } 67 Groupings Sister Clades } } } 68 Groupings Sister Clades } } } Camels are sister to the rest of this tree, not “basal” to it 69
Image of page 11

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

Vertebrate Relationships Linnaean Classification Amphibia Mammalia Testudines Reptilia Aves Crocodylia Squamata 70 Linnaean Classiciation Traditional Class Amphibia Class Reptilia Order Testudines Order Crocodylia Order Spenodontida Order Squamata Class Aves Class Mammalia 71 Rank Free Classification Traditional Class Amphibia Class Reptilia Order Testudines Order Crocodylia Order Spenodontida Order Squamata Class Aves Class Mammalia Phylogenetic Classification Tetrapoda Amphibia Amniota Mammalia Reptilia Testudines Sauria Archosauria Aves Crocodylia Lepidosauria Sphenodontida Squamata Phylocode : a formal set of rules governing the use of phylogenetic nomenclature 72
Image of page 12
Vertebrate Relationships Rank Free Classification Tetrapoda Amphibia Amniota Mammalia Testudines Reptilia Sauria Archosauria Aves Crocodylia Lepidosauria Labels in blue are not part of formal Linnaean classification Note: Turtles are probably sister to the Archosaurs, not Sauria 73 Tree parts: Node, Internode (=Branch), Tip, Root, Outgroup, Ingroup, Rooted, Unrooted Groups: Monophyly, paraphyly, polyphyly, clade, sister taxa Traits: Apomorphy (=derived), synapomorphy (=shared, derived), plesiomorphy (=ancestral), symplesiomorphy (shared, ancestral) Trait similarity: Homology, homoplasy, convergence, parallelism, reversal
Image of page 13

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

Image of page 14
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '18
  • MORRIS
  • Cladistics, Phylogenetics, Internode

{[ 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