BIOL 152 9thEdition Lecture 8 Outline of Last Lecture I Life on Earth II The First Cells III Classifying Life Outline of Current Lecture I Morphological and Molecular Homologies II Sorting Homology from Analogy III Evaluating Molecular Homologies Current Lecture 26 2 Phylogenies are inferred from morphological and molecular data Phylogenies built using homologies in o Morphologies o Genes o Biochemistry I Morphological and Molecular Homologies o Similarities due to shared ancestry homologies Can inform relatedness o basic ingredients what was there o Mutations that are selected lead to II Sorting Homology from Analogy o Analogy is a similarity due to convergent evolution Similar selective pressures o Homoplasy analogous structures or molecular sequences that evolved independently Check fossil record to determine homologies or homoplasies The more complex the more likely it is homologous III Evaluating Molecular Homologies o Statistics Help evaluate relatedness Examine different DNA segments and determines homology or homoplasy These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Molecular systematics uses DNA and other molecular data to determine evolutionary relationships 26 6 New Information continues to revise our understanding of the tree of life Later 5 Kingdoms Still relevant Anamalia Plantae Fungi Currently 3 Domains o Bacteria o Archaea o Eukarya A simple tree of all life o The tree of life Eukaryotes and archaea more related to each other than to bacteria o Tree of life built using rRNA genes highly conserved Horizontal gene transfer complicates efforts to build a tree of life Is the tree of life really a ring o Some researchers suggest that eukaryotes arose as a fusion between a bacterium and archaean o If so early evolutionary relationships might be better depicted by a ring of life instead of a tree of life