CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 20 Phylogeny

© 2014 Pearson Education, Inc.  Phylogeny - evolutionary history of a species or group  systematics classifies organisms and determines evolutionary relationships  Taxonomy is the ordered division and naming of organisms

© 2014 Pearson Education, Inc. Binomial Nomenclature  In the 18th century, Carolus Linnaeus published system of taxonomy based on resemblances (Linnaean system)

© 2014 Pearson Education, Inc. Binomial Nomenclature Binomial Nomenclature - 2 name naming system The Scientific name (Binomial) is the Genus name followed by the species name Genus name starts with a capital letter the rest is lower case Species name is never written without at least the first initial of the genus name Binomials are written in italics (or a contrasting writing style) Binomials are Latin or “Latinized”

© 2014 Pearson Education, Inc. Taxonomy Domain (Largest and Most General) Kingdom Phylum Class Order Family Genus Species (Smallest and Most Specific)

© 2014 Pearson Education, Inc. Taxonomy Inbetween levels are used where necessary Kingdom Subkingdom Superphylum Phylum Subphylum Superclass Class Subclass Superorder…and so on….

© 2014 Pearson Education, Inc. Figure 20.3 Species: Panthera pardus Kingdom: Animalia Domain: Archaea Domain: Bacteria Domain: Eukarya Genus: Panthera Order: Carnivora Family: Felidae Class: Mammalia Phylum: Chordata

© 2014 Pearson Education, Inc. Linking Classification and Phylogeny  Systematists depict evolutionary relationships in branching phylogenetic trees

© 2014 Pearson Education, Inc. Figure 20.4 Panthera pardus (leopard) Species Order FamilyGenus Taxidea taxus (American badger) Canis latrans (coyote) Lutra lutra (European otter) Canis lupus (gray wolf) Panthera Taxidea Canis Lutra Felidae Mustelidae Carnivora Canidae 12

© 2014 Pearson Education, Inc.  A phylogenetic tree represents a hypothesis about evolutionary relationships  Each branch point (node) represents the divergence of two taxa  Sister taxa are groups that share an immediate common ancestor

© 2014 Pearson Education, Inc. Figure Branch point: where lineages diverge This branch point represents the common ancestor of taxa A−G. This branch point forms a polytomy: an unresolved pattern of divergence. ANCESTRAL LINEAGE Sister taxa Basal taxon Taxon A Taxon B Taxon C Taxon D Taxon E Taxon F Taxon G

© 2014 Pearson Education, Inc. Cladistics  Cladistics classifies organisms by common descent  A clade is a group of species that includes an ancestral species and all its descendants

© 2014 Pearson Education, Inc.  A valid clade is monophyletic, signifying that it consists of the ancestor species and all its descendants

© 2014 Pearson Education, Inc. Figure 20.10a B C A D E F G Group I (a) Monophyletic group (clade) 1

© 2014 Pearson Education, Inc.  A paraphyletic grouping consists of an ancestral species and some, but not all, of the descendants

© 2014 Pearson Education, Inc. Figure 20.10b B C A D E F G Group II (b) Paraphyletic group 2

© 2014 Pearson Education, Inc.  A polyphyletic grouping consists of various taxa with different ancestors

© 2014 Pearson Education, Inc. Figure 20.10c (c) Polyphyletic group B C A D E F G Group III 1 2

© 2014 Pearson Education, Inc. Shared Ancestral and Shared Derived Characters  In comparison with its ancestor, an organism has both shared and different characteristics

© 2014 Pearson Education, Inc.  A shared ancestral character is a character that originated in an ancestor of the taxon  A shared derived character is an evolutionary novelty unique to a particular clade

© 2014 Pearson Education, Inc. Figure 20.11b Leopard Turtle Frog Bass Lamprey Lancelet (outgroup) Hair Amnion Four walking legs Hinged jaws Vertebral column (b) Phylogenetic tree

© 2014 Pearson Education, Inc. Figure Forams Ciliates Euglenozoans Diatoms COMMON ANCESTOR OF ALL LIFE Land plants Animals Amoebas Fungi Red algae Chlamydias Green algae (Mitochondria)* Methanogens Proteobacteria Nanoarchaeotes Thermophiles Domain Eukarya Gram-positive bacteria (Chloroplasts)* Spirochetes Cyanobacteria Domain Bacteria Domain Archaea

© 2014 Pearson Education, Inc. Figure 20.2 ANCESTRAL LIZARD (with limbs) Eastern glass lizard Monitor lizard Snakes Geckos No limbs Iguanas No limbs

© 2014 Pearson Education, Inc. Figure 20.1