Exercise 1 - Backyard Inventory

• Systematics is a science that deals with the reconstruction of phylogeny or evolutionary history of organisms.
• This branch of science encompasses taxonomy which comprises description, identification,  nomenclature and

  classification of organisms.
• In description, a particular character (e.g. leaf shape) can have varied

  character states.
• These descriptions are organized  into taxonomic keys or dichotomous  keys which are essential in the recognition of unknown organisms or identification. 
• Species are named following a scientific  and formal naming or  nomenclature
• International Code of Botanical Nomenclature (ICBN) is generally used.  
• The binomial nomenclature also applies which consists of two names: Genus and Species
• Classification involves the arrangement of entities.
• In classification, a hierarchical structure is used from broadest to specific level (taxonomic rank or taxon, sing.) (e.g. domain, kingdom, division (phylum), class, order, family, genus, and species) 
• The classification has two types: a.) Phenetic classification that is based on the overall similarity between and among taxa, and b.) Phylogenetic classification which is through the evolutionary history or pattern of descent (e.g. characters or traits) between ancestral organisms and its descendants.
• A branching diagram or tree structure is used that conceptually illustrates the pattern of descent wherein lines in the diagram represents lineages or clades.
• “Cladogram” is used since the lengths of lines are arbitrary and do not denote time or genetic distances
• The change from pre-existing character or ancestral character state into a new derived character state or evolutionary novelty, called as an apomorphy.
• “Phylogenetic tree” is the evolutionary pattern has time and genetic distance components as they can be generated.
• Plant collections are preserved and stored in an herbarium and referred as an herbarium specimen.
• Herbarium specimen. These plant samples are usually pressed and dried and are then glued or permanently attached to a sheet of paper with documentation labels.