taxonomy

• Taxonomy - The branch of biology concerned with describing, naming, identifying and classifying organisms.
• Description - is the assignment of features or attributes (characters) to a taxon
• Nomenclature - the formal naming of taxa according to some standardized system. For plants, fungi, and algae, rules for naming are provided by the International Code of Botanical Nomenclature. For animals, rules on naming are based on the International Code of Zoological Nomenclature
• Identification - is the process of associating an unknown taxon with a known one
• Classification – method of grouping organisms; arranging entities into some type of order to provide a system for cataloguing and expressing relationships between these entities 
• Taxonomy - Swedish naturalist Carolus Linnaeus (1707-1778) devised a system of grouping organisms into hierarchical categories according to their form and structure. Each category represents a level of grouping from larger, more general categories to smaller, more specific categories.
• Linnean method - it is artificial since organisms are classified based on morphological similarities and not on evolutionary relationships.
• types of morphological

  homology

  analogy
• Taxanomy - It is a hierarchical system since organisms are grouped into ever more inclusive categories from species up to kingdom.

  
  

  Linnaeuys original system had seven levels.
• Taxon

  • Any group or rank in a biological classification into which related organisms are classified.
  • Plural is taxa
• Carl Woese - he proposed a category higher than a kingdom, called domain

  
• What are under the Domain:

  BAE

  Bacteria

  Archae

  Eukarya
• The Binomial System

  • Nomenclature refers to the practice of assigning scientific names.
  • Binomial comes from the words “bi” meaning “two” and “nomen” meaning “name”.
  • A species name consists of two parts: the genus or generic name and the specific epithet.
  • The first letter of the genus is always capitalized (e.g. Canis) while the specific epithet is not capitalized (e.g. familiaris). One can distinguish a species name from the way it is written. Species name can be in bold letters or underlined or italicized.
• Nomenclature - refers to the practice of assigning scientific names.
• Binomial comes from the words “bi” meaning “two” and “nomen” meaning “name”.
• A species name consists of two parts:

  these are

  the genus or generic name

  the specific epithet.
• subspecies - Biologists refer to variations of a species that live in different geographic areas. It is a population within a species that forms its own group and takes on some new characteristics.

  
• DICHOTOMOUS KEY

  • a tool that helps identify unknown organisms to some taxonomic level.
  • "Dichotomous" means "divided into two parts.”
• systematics- the study of the diversity of organisms at all levels of organization
• Phylogeny - the study of the evolutionary history and relationships among organisms.
• Phylogenetic tree - This type of diagram looks like a family tree and has a branching pattern that indicates how closely related a subset of taxa are thought to be.

  
• Name each parts:

  ---

  1. root
  2. branch point
  3. basal taxon
  4. polytomy
  5. sister taxa

  
• root - indicates that an ancestral lineage gave rise to all organisms on the tree.
• branch point - indicates where two lineages diverged.
• basal taxon - a lineage that evolved early and remains unbranched
• sister taxa - two lineages stem from the same branch point
• polytomy - a branch with more than two lineages
• who develops cladistics?

  Willi Hennig
• Character - any trait of an organism that can be described or measured

  ex: Corolla
• Character state - describes the character

  ex: shape of the corolla, color of corolla, number of petals comprising the corolla.
• shared character - A feature that all members of a group have in common 

  
  

  ex: Shared example hair in mammals or feathers in birds.
• Derived character - A feature that evolved only within the group under consideration. 
• Cladogram - a phylogenetic tree that shows the relationship of taxa based on shared derived characters.
• Clada - a group of taxa consisting of an ancestor and all of its descendant taxa shared derived character can refer to the loss of a feature, such as the loss of limbs in snakes or whales. Also, keep in mind that it is a relative matter whether a character is considered ancestral or derived.
• out-group - an organism that is distantly related to the other organisms. It is a starting point or comparison with the other organism being evaluated.