Biological Classification Terminology, Methods and Representative Systems

Systematics The Study of Biological diversity

Taxonomy the science of naming and classifying organisms

Binomial Nomenclature Two name naming system Genus specific epithet, usually a latinized descriptive Linnaeus (mid 18th century) developed binomial naming system: developed by Linnaeus (mid 18th century) Latinize this!

The rules of binomial nomenclature Home sapiens H. sapiens Escherichia coli E. coli Genus is always capitalized Specific Epithet is NEVER capitalized The entire name is either italicized or underlined Full words upon first mention in text, abbreviate thereafter.

Why a naming system? the same organism may have more than one name in different languages or different regions the same common name is often applied to more than one organism, e.g. daisy many common names are confusing, e.g. a pineapple tree is neither a pine nor apple there are no rules for using common names, with millions of named species there must be some rules

Taxonomic Heirarchy King Philip Came over for good sushi! (nudge, nudge….say no more! Kingdom, phylum, class, order, family, genus, species, Domainstrain Share general characters Share specific characters

The higher the category, the more inclusive it is Members of a kingdom share general characters; members of a species share quite specific characters Characters are any structural, chromosomal, or molecular feature that distinguishes groups Additional levels of classification can be added by adding super-, sub-, or infra- (e.g., suborder, subspecies).

Here is this example with the names of the categories. Phylum – Chordata Subphylum – Vertebrata Class – Mammalia Order – Primates Family –Hominidae Genus – Homo Species – Homo sapiens subspecies sapiens subspecies neanderthalensis Homo erectus Homo ergaster Homo habilis

There are two ways to organize 1.Phenetic - based on overall similarity of form and structure. Must be based on homologous, not analogous features Homologous structures - similarity in structure due to common descent, may have diverse uses E.g. vertebrate forearms: human hand, bat wing, dolphin flipper. Analogous structures - similarity in structure based on adaptation for the same function, not common descent. E.g. wings in insects, reptiles, birds, and bats.

There are two ways to organize 2.Phylogenetic - based on common evolutionary descent –Phylogeny = the evolutionary history of a group of organisms Now the preferred method because it has predictive value Modern phylogenetic investigations are based on molecular data, primarily nucleotide sequences. Basically, the more closely related two organisms are, the more nucleotide sequences (genes) they will have in common.

Monera ProtistsPlantaeFungiAnimalia Eukarotes (Eukarya) BacteriaArchae 3 Domain System (Woese, 1990) 5 Kingdom System (Whittaker, 1969)

Synthesis: six kingdoms (Cavalier-Smith 1998) Superkingdom Prokaryota Kingdom Bacteria Superkingdom Eukaryota Kingdom Protozoa Kingdom Animalia Kingdom Fungi Kingdom Plantae Kingdom Chromista

3 domain System