Chapter 18 Taxonomy

How many new species are discovered each year?

18.1 History of Taxonomy  Taxonomy defined Science of grouping organisms based on presumed natural relationships Can be applied to multiple disciplines

When, Who, How  2000 years ago  Aristotle Where they lived  Water  Land  Air Stem differences 1 AD Problems?

Common Names  Every day names given to organisms  Problems?

Carolus Linnaeus  Swedish naturalist  1707 – 1778  Developed system of grouping organisms based on hierarchical categories  Used morphology  Not phylogeny

Linnaeus’s Hierarchy

Your Classification  KingdomAnimalia  PhylumChordata  SubphylumVertebrata  ClassMammalia  OrderPrimates  FamilyHominidae  GenusHomo  Speciessapiens

Binomial Nomenclature  2 name name given to each organism  Includes genus and species  Species name is its identifier  Underline/italicize both  Capitalize genus  Ex: Mus musculus  Scientifically names each organism  Based on Latin language

Additional Key Terms  Division Used instead of phylum for plants  Subspecies Subspecies Morphologically different geographically separated  Variety Variety Morphologically different Not geographically separated  Strain Strain Biochemically different group within a species Represented by letters or numbers