Making the Connection TAXONOMY science of describing, naming and classifying organisms Modern Systematics Phylogenetics Phylogenetic tree Cladistics Cladograms Traditional Linnaean System

TRADITIONAL Linnaean System – 1735, Systema Naturae ranks organisms by categories according to form & structure. Represented by hierarchical levels King Phillip Came Over For Ginger Snaps

Classification should reflect Phylogeny MODERN Systematics - Describing, classifying and naming organisms in terms of their natural relationships Natural relationships = physical features, embryos, genes in the nucleus, DNA & RNA Classification should reflect Phylogeny

Phylogenetics - Hypothesis of the evolutionary history of species or taxonomic group Compare visible similarities among current living or fossils or compare chromosomes and macromolecules Represent hypotheses in the form of Phylogenetic diagram also called Phylogenetic tree

Phylogenetic tree – Evolutionary tree or Tree of Life Charles Darwin 1837 Transmutation of Species Charles Darwin 1859 The Origin of Species by Means of Natural Selection Ernst Haeckel 1866 Monophyletic tree of organisms

Darwin’s First Tree This is alleged to be Darwin's first sketch of an evolutionary tree of life (circa 1837) taken from his First Notebook on Transmutation of Species, which is viewable at the the Museum of Natural History in Manhattan, New York City..

The Origin of Species, 1859

Origin of Species Ch 13 "The affinities of all the beings of the same class have sometimes been represented by a great tree... The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was small, budding twigs; and this connexion of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. . . As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all a feebler branch, so by generation I believe it has been with the Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications" (Charles Darwin, 1859).

Ernst Haeckel Monophyletic tree of organisms 1866 Evolutionary tree that included all forms of life with a universal common ancestor

CLADISTICS Developed by Willi Hennig in 1966, A phylogenetic classification system that uses shared & derived characters as the only criteria for grouping taxa Shared character – feature that all members of a group have in common Derived character – feature that evolved only within the group under consideration

CLADISTICS Clad – group of organisms that include an ancestor plus all of its descendants Represented by a Cladogram – hypothesis phylogenetic diagram of evolutionary relationship between a group

NAILING CLADASTICS Take out your worksheets. What characteristics did you use to organize organisms? How did you design your table? Compare and contrast Cladograms.

Cladogram Group

Cladogram of vertebrate animals Ingroup Outgroup

Trees Portray Clades

Interpreting a Phylogenetic Tree Nodes: Organism at base of tree is common ancestor to all the others in the tree. Sister Groups: Branch points indicate the evolution of some characteristic that splits a group into two groups. Groups shown at tips of branches include organisms that have evolved most recently.

Major Revision of the Classification System When looking at the cells of any living organism what 2 fundamental types of cells can you identify? EURKARYOTES & PROKARYOTES

NEW TREE OF LIFE 1977, Carl Woese began grouping organisms by their genetic (RNA) similarities Phylogenetic tree drawn from his RNA grouping shows that living things seem to fall into 3 broad groups or domains and an additional kingdom

Redrawing The Classifications of Life

Tree of Life

TREE OF LIFE FLOW CHART http://cmapsnasacmex.ihmc.us/servlet/SBReadResourceServlet?rid=1025200161531_1068066319_1715&partName=actualhtmltext

ANY QUESTIONS?

HOMEWORK WHAT DO YOU THINK??? Due 5/5/09 List three ways of how evolutionary trees are used. Read p 346 – 351 QUIZ???