Fig. 26.7a. Biodiversity. 1. Course Outline Outcomes Instructors Text Grading. 2. Course Syllabus. Fig. 26.7b Table

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1 Fig. 26.7a Biodiversity 1. Course Outline Outcomes Instructors Text Grading 2. Course Syllabus Fig. 26.7b Table

2 Table Outline: Systematics and the Phylogenetic Revolution I. Naming and Classifying organisms Binomial Nomenclature Naming Organisms Taxonomy - The Science of Classifying Organisms Hierarchy of Classification II. Understanding how diversity got here Systematics The Science of Constructing and Studying Phylogenies Cladistics The tool of Systematics to construct phylogenies III. Molecular data are revolutionizing taxonomy Protists are polyphyletic 200,000 species Fungi a common molecular heritage with animals? IV. The Kingdoms of Life Three domains Archaebacteria, Bacteria, and Eukarya Six-kingdom Eukaryotic: Animalia, Plantae, Fungi, & Protista Prokaryotic: Archaebacteria & Bacteria Viruses: A Special Case Nomenclature: Naming Organisms Binomial Nomenclature system by Carolus Linnaeus about 250 years ago. binomial - two-part name for each species Genus + specific epithet Name given to a species Examples of Binomials Homosapiens Homo sapiens - humans Acerrubrum Acer rubrum - Red maple Felis domesticus Felis domesticus - Cat Felis concolor Felis concolor mountain lion What is a Species? Definition of a species Interbreeding population Potentially breeding population Inherent willingness to interbreed Production of fertile, viable offspring 2

3 Classification Taxon = group of organisms at a particular level in a classification system. Classification Hierarchy of Classification Domain Kingdom Phylum Class Order Family Genus species Domain Largest & most inclusive Species Basic unit of classification Classification Classification 3

4 Hierarchical system of classification Species Genus Family Order Class Phylum Kingdom Domain Systematics & Phylogeny Darwin envisioned that all species were descended from a single common ancestor He depicted this history of life as a branching tree. Tree = phylogeny Systematics & Phylogeny Systematics & Phylogeny & Cladograms Twigs of a tree represent existing species Joining of twigs and branches reflects the pattern of common ancestry back in time to a single common ancestor Darwin called this process descent with modification Cladogram = diagram of evolutionary relationships a phylogeny 4

5 Studying Evolutionary Relationships Phylogeny = a hypothesis Systematics = branch of biology attempts to reconstruct phylogenies study of evolutionary relationships Cladistics = analytical tool Distinguishes similarity inherited from the most recent common ancestor Shared, derived characters are informative to reconstruct phylogenies Cladistic Method of Constructing a Phylogeny Characters are first considered Character = Any aspect of phenotype Character states Character is present or absent Clade Groups with shared-derived characters Cladistic Analysis & Outgroup Comparison Outgroup Derived Characters (Traits) Cladogram a phylogeny Vertebrate = Ancestral Character State 5

6 Bird Evolution Cladistics & Molecular Phylogeny A Cladogram of DNA analysis HIV & Disease Evolution 6

7 Interpreting A Cladogram Monophyletic Group Interpreting A Cladogram Paraphyletic Group Common Ancestor All Descendants Included Common Ancestor Not all Descendants included Polyphyletic Group Interpreting Cladistics with Classification Monophyletic group Includes recent common ancestor and Includes all of its descendants. Paraphyletic group Includes most recent common ancestor Does not include all of its descendents. Common Ancestor? Descendants? Polyphyletic group Does not include most recent common ancestor Does not include all the members. 28 7

8 What does a Cladogram Reveal? 1. Establishes ancestral similarity found in a common ancestor 2. Reveals derived similarity - within a group 3. Shared, derived characters provide information about evolutionary relationships A. Clades are evolutionary units related by 1.common ancestry and shared, derived characters. B. Clade nodes (branching points) reveal how closely related two species are C. Cladograms indicate order of evolutionary branching events D. Cladograms do not time evolutionary events Classification of Life LIFE Cell type? Prokaryote Eukaryote Common Bacteria Extreme bacteria Simple/ single cells Many cells Domain Bacteria Domain Archaea Autotrophs Heterotrophs Domain Eukarya absorptive ingestive KINGDOM Bacteria Archaebacteria Protista Plant Fungi Animal Fig Endosymbiosis END Ancestral Prokaryote 8