Taxonomy Chapter 18

Taxonomy  Field in which scientists classify organisms and assign a universally accepted name  Organization into groups that get more and more specific  All levels share common features  Ex: Mammalia, Vertebrata, Canis

Classification System  Each level is called a “taxon”  7 total levels*  Kingdom—Phylum—Class—Order— Family—Genus—Species  Most general at the top (most members)  Most specific at the bottom (least members)  *Not including Domains (yet)

Ex: Red Tailed Hawk Classification  Kingdom: AnimaliaAnimalia  Phylum: ChordataChordata  Class: AvesAves  Order: FalconiformesFalconiformes  Family: AccipitridaeAccipitridae  Genus:Buteo  Species: jamaicensis

What is Binomial Nomenclature?  Modern classification for organisms using a two-word naming system  The 2 words are the last 2 taxonomic levels: Genus and species Example: Periplaneta americana = A Cockroach!!!

How did we find that?  Classification  Kingdom: AnimaliaAnimalia  Phylum: ArthropodaArthropoda  Class: InsectaInsecta  Order: BlattariaBlattaria  Family: BlattidaeBlattidae  Genus: Periplaneta  Species: americana

How do we write scientifically?  Capitalize the Genus  Lowercase the species  Either: Italicize or Underline the grouping  Ex: Carcharodon carcharias  Ex: Ara macao

Who came up with this system?  Carolus Linnaeus  Loved Latin so much changed his name to the Latin form…sweet.  Came up the hierarchal classification system  Founder of modern taxonomy

What is Phylogeny?  Evolutionary History of Species  Shows Relationships and Common Ancestors  Uses a “Phylogenetic Tree” to shows relationships  Based on: Structural Similarities, Breeding Behavior, Geographic Distribution, Chromosome Comparisons, & Biochemistry  Presumed relationships based on MORPHOLOGY!!  = structural features!

How do you read the tree?  Is the “Oldest” at the bottom? Yes and No, the tree shows common ancestors!  What is our most common ancestor on this tree?

What is Cladistics?  Branch of taxonomy that uses cladograms to show relationships

Cladogram Construction  a stylized diagram that looks like a series of Y's or forks in a road  At each branch, or "Y" junction, characteristics of evolutionary origin are used to separate one group from the rest.  All the organisms after that characteristic will share that trait.  Used to show common ancestry

Cladogram