Systematics The Science of Biological Diversity Topic 1 Learning Objectives Plant Diversity BOT 3015 Dr Mast 1 What is the broad goal of systematics Explain the significance of this a Systematics the scientific study of biodiversity and its evolutionary history i The broad goal of systematics is to discover all of the branches of the phylogenetic tree of life b Tree of Life Evidence from morphological biochemical and gene sequence data suggests that all organisms on Earth are genetically related and the genealogical relationships of living things can be represented by a vast evolutionary tree the Tree of Life The Tree of Life then represents the phylogeny of organisms i e the history of organismal lineages as they change through time It implies that different species arise from previous forms via descent and that all organisms from the smallest microbe to the largest plants and vertebrates are connected by the passage of genes along the branches of the phylogenetic tree that links all of Life c Phylogeny the evolutionary relationships among organisms Phylogeny the genealogical map for all lineages of life on earth provides an overall framework to facilitate biological information retrieval prediction and analysis Assembly of a framework phylogeny or Tree of Life for all major lineages of life requires a greatly magnified effort often involving large teams working across institutions and disciples specimens 2 What are the activities of taxonomy What role does a type specimen play in taxonomy Where can one find type a Taxonomy the identifying naming and classifying of species i 80 completion for plant naming ii 1 5 million species of fungi only 99 000 named iii 17 completion for naming and describing all species b International Code of Botanical Nomenclature governs naming of plants photosynthetic protists and fungi i Latin description can now be in English ii Updated every 6 years Melbourne in 2011 c Type Specimen identified when published type anchors name i Often held in herbarium for basis of comparisons with other specimens in determining whether they are members of the same species ii Each name has a type specimen which anchors the name 3 What is biodiversity informatics a Biodiversity informatics the application of informatics techniques to biodiversity information The b herbarium database and website is an example iDigBio a joint project between FSU and UF iDigBio is the National Resource for Advancing Digitization of Biological Collections c Bio Blitz a census of species in a given area in 24 hours which gives historic baseline for comparison a baseline for environmental change 4 What percentage of the world s plant and fungal species have been named How many extant species of each are estimated to exist a 80 completion for plant naming b 17 completion for naming and describing all species c 7 complete for fungi d 1 5 million species of fungi only 99 000 named 5 Explain the historical context in which the binomial system of nomenclature emerged Identify the parts of a binomial Which part is meaningful by itself Compare the utility of common vs scientific names a Carl Linnaeus published species plantarum described each species in Latin in a sentence limited to 12 words i e polynomials i Created the two term naming system binomial 1 The first part of the name identifies the genus to which the species belongs the second part identifies the species within the genus For example humans belong to the genus Homo and within this genus to the species Homo sapiens b Composed of Genus Specific Epithet and Author i Solidago sempervirens L genus specific epithetic not useful by itself can be reused author 6 What categories are used in biological classification How are these hierarchically related a Taxon a taxonomic group of any rank b Classification The arrangement of entities in a hierarchical series of nested classes in which similar or related classes at one hierarchical level are combined comprehensively into more inclusive classes at the next higher level A class is defined as a collection of similar entities c The level of which it is ranked is called a category i Ex genus and species are categories and Prunus and Prunus Persica are taxa in those categories Kingdom phylum division class order family genus species 7 What distinguishes an artificial classification from a natural one a Artificial system of classification classify organisms primarily as an aid to identification and generally by a few characters i Linnaeus sexual system is an artificial system of classification by which plants were classified into 24 classes based on the number and arrangements of the stamens in each flower ii Everyone with X amount of stamens and Y pistils grouped together b Natural system of classification accurate reflection of the evolutionary relationships among i The Angiosperm s Phylogeny Group s classification is a natural system of classification c Phylogeny The evolutionary relationships among organisms organisms 8 Identify monophyletic paraphyletic and polyphyletic groups on a phylogeny Be able to distinguish between diagrams of phylogenies that differ in a significant way as opposed to a superficial rotation of a clade etc a Monophyletic group clade composed of an ancestor and all its descendants none of descendants are excluded Genus should consist of all species descended from the most recent common ancestor and only of species from that ancestor i Can be removed from the tree by simply one cut b Paraphyletic group a group composed of a common ancestor but not all decedents of that ancestor i Some may not be included because of divergent evolution c Polyphyletic group a group that excludes the most recent common ancestor of all members In other words a group with two or more ancestors but not including the true common ancestor of all its members d Clade a group consisting of an ancestor and all its descendants a single branch on the tree of life i The ancestor can be indicated by its relation to two or more specifiers that are mentioned explicitly This can be done in three ways Node based Stem based and Apomorphy based 9 In what way have the kinds of characters used to reconstruct phylogenies changed How are phylogenies reconstructed a Cladistics a system of arranging organisms following an analysis of their primitive and advanced features so that their phylogenetic relationships are accurately reflected i The approach focuses on the branching of one lineage from another in the course
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