Systematics: The Science Of Biological Diversity Chapter 12 Systematics- the scientific study of biological diversity and its evolutionary history.

Theophrastus (370-285 B.C.) Father of Botany, student of Aristotle. Classified plants based on form. Tree Shrub Undershrub Herb

Atropa belladonna- Solanaceae

Carol von Linné (1707-1778) Swedish naturalist. Systema Naturae & Species Plantarum. Plant descriptions. Plant binomials- a two-term system of nomenclature. Genus and species (specific epithet). Example- catnip. Nepeta cataria L. “Nepeta floribus interrupte spicatus pedunculatis”

Nepeta cataria- Lamiaceae

Taxonomy Taxonomy- (gr. taxis- arrangement, nomos- law) the science of the classification of organisms. Identifying, naming, classifying organisms. Domain Kingdom Phylum- phyta Class- phyceae Order- ales Family- aceae Genus Species

Prokaryotes and Eukaryotes

Eukaryote Lineages

Origin of Cells

Origin of Eukaryotic Cells

Species Concepts

International Code of Botanical Nomenclature (ICBN) Aim- to provide a stable method of naming taxonomic groups. Principle I- botanical nomenclature is independent of zoological and bacteriological nomenclature. Principle II- names of taxonomic groups are determined by means of nomenclatural types. Principle III- nomenclature of a taxonomic group is based upon priority of publication. Naming- the purpose of giving a name to a taxonomic group is not to indicate its characters or history, but to supply a means of referring to it and to indicate its rank.

Taxonomic Terminology Taxon- a taxonomic group of any rank (plural: taxa). Synonym- two or more names that apply to the same taxon. Basionym- the original name of a taxon. Author/s- the first person or persons to describe a taxon. Revisionary author/s- the person or persons that modified the name. Etymology- the derivation, origin, or history of a word. Type Specimen- a specimen designated to serve as a reference point for a scientific name. Holotype Lectotype

Taxonomic Names Species names consists of the genus name, plus the specific epithet. Members of a species may be grouped into subspecies or varieties.

How do you identify plants? Ask an expert Use a herbarium Compare plant with a written description Use books to picture I.D. specimens Photographs and illustrations. Use a dichotomous key Analyze DNA sequence from specimen

Dichotomous Keys A method employed for identifying unknown organisms. A dichotomous key is constructed of a series of couplets, each consisting of two separate statements. 1. Flowers white .................. Plant A 1. Flowers red or yellow ..... 2 2. Petals red ............ Plant B 2. Petals white ........ Plant C