Module 7 Classification and Systematics PDF

Module 7 Classification and Systematics TAXONOMY Classification and Systematics Taxonomy is the science of naming, describing, and classifying organisms including plants, animals, and even microorganisms. It is a component of systematics that focuses more on the theory and practice of classificati...

Module 7 Classification and Systematics TAXONOMY Classification and Systematics Taxonomy is the science of naming, describing, and classifying organisms including plants, animals, and even microorganisms. It is a component of systematics that focuses more on the theory and practice of classification. Taxonomy and systematics are not clearly separable but are frequently used by biologists interchangeably. Classification • Classification is the systematic arrangement of organisms in groups or categories according to an established specific criterion. Systematics • Systematics is the study of biological diversity of organisms and their natural evolutionary relationship to other organisms and their environment. PHYLOGENY • Phylogeny – the study of evolutionary history and relationship of organisms that descend from one or more ancestry o Monophyletic Groups – consists of organisms that evolved from one common ancestry o Polyphyletic Groups – groups of organisms that has several evolutionary lines without common ancestry o Paraphyletic Groups – consists of organisms that includes a common ancestor, but not all its descendants CLADISTICS • • • Cladistics – classification of an organism based on recency of common ancestry rather than the degree of structural similarity. o Cladogram – a diagram that illustrates evolutionary relationship based on the principles of cladistics. The general goal of cladistics is to reconstruct phylogenies using an analysis of evolutionary changes in specific. Steps in making a Cladogram 1. Select groups. 2. Select homologous character to be analyzed. 3. Organize the character states into their correct evolutionary orders CHARACTERS TAXON VASCULAR TISSUES SEEDS FLOWERS MOSS A A A FERN P A A PINE P P A DAISY P P P A = ABSENT | P = PRESENT mlsolidarIos 5 All the plant groups except mosses have vascular tissues. Seeds are shared characteristics for all plant groups except mosses and ferns. Daisy is the only plant that produces flowers. BINOMIAL NOMENCLATURE Binomial Nomenclature is a system for giving each organism a two-word scientific name. Specific Epithet • Specific Epithet in a binomial nomenclature is the second part uncapitalized part of the scientific name of an organism that follows the genus and often describes a particularity of an organism. • Species – the basic unit of classification o Sub-species (interbreed) - geographically distinct population that evolved by Natural Selection o Cultivar – cultivated varieties of plants. These species are not equivalent to sub-species o Dichotomous Key – allows taxonomist to determine the identity of organisms based on keys that consists a series of choices that lead to correct identity PIONEERS OF PLANT CLASSIFICATION • • • Theophrastus – classified plants into herbs, shrubs, and trees Dioscorides – his De Materia Medica described 600 species of medicinal plants and was widely used a medical reference for about 1500 years until the end of the Middle Ages Carolus Linnaeus – wrote Species Plantarum, which contains description of plants that were known in his time. He observed 7300 species of plants and provided each plant with a binomial name. ~ END OF MODULE 7 ~ mlsolidarIos 6