Download Understanding Systematics: Study of Biological Diversity & Evolutionary Relationships and more Study notes Biology in PDF only on Docsity! 1 1 “Systematics is the study of biological diversity and its origins. It focuses on understanding evolutionary relationships among organisms, species, higher taxa, or other biological entities, such as genes, and the evolution of the properties of taxa including intrinsic traits, ecological interactions, and geographic distributions. An important part of systematics is the development of methods for various aspects of phylogenetic inference and biological nomenclature/classification.” -Systematic Biology editorial board 2 Systematics Study of: • the kinds and diversity of organisms (http://www.msnbc.msn.com/id/11114156/) • the relationships among them • taxonomy and systems of classification 3 Effigia okeeffeae Archosaur - 210 my Harpymimus okladnikovi Dinosaur - 120 my 4 5 6 Cow Horse Salamander Gecko Time Phylogenetic Tree or cladogram • Topology • Hypothesis 2 7 Time Cladogenesis Anagenesis 8 Taxon (pl. Taxa) Terminal Branch or Tip Internal Branch Nodes 9 Cow Horse Salamander Gecko Rotation of branches 10 Cow Horse Salamander Gecko No change in topology 11 Cow Horse Salamander Gecko New topology 12 Cow Horse Salamander Gecko • Monophyletic group • Natural group • Clade 5 25 Cow Horse Salamander Gecko Vertebrae Fur Lactation Horns Alternate character mapping method 26 Cow Horse Salamander Gecko Vertebrae Fur Lactation Horns 4 step tree 27 No. taxa No. rooted trees 2 1 3 3 4 15 5 105 10 3 X 107 50 3 X 1077 1000 4 X 102,864 28 c h g s c h g s c g h s c s h g c h s g c s g h c g h s c g s h c s g h h s c g h s g c h g c s h g s c s g h c s g c h The 15 possible trees for 4 taxa 29 Cow Horse Salamander Gecko Vertebrae Fur Lactation Horns 6 step tree 30 Cow Horse Salamander Gecko Vertebrae Fur Lactation Horns 4 step tree 6 31 1 2 3 4 5 V F L H C Cow 1 1 1 1 1 Horse 1 1 1 0 0 Gecko 1 0 0 0 1 Salamander 1 0 0 0 0 Data matrix 32 Cow Horse Salamander Gecko Vertebrae Fur Lactation Horns 6 step treeBrown colorHomoplasy 33 The Outgroup • Used to “root” the phylogenetic tree • Differentiate shared, ancestral character states from shared, derived ones 34 Kennedy (1929) Phylogeny – a branching diagram representing the evolutionary relationships or history of genes, species or other taxa. A brief history of Systematics 35 36 Willi Hennig 7 37 David Swofford FSU 38 Today’s Goals 1. Construct a phylogeny of vertebrates using the “vertebrate example” data set 2. Construct a phylogeny for eight primate species using skulls in the lab. 39 Using Mesquite Analysis of phylogeny & character evolution
