ISMB-97: Intelligent Systems for Molecular Biology 1997 Gelfand Tutorial

The Fifth International Conference on Intelligent Systems for Molecular Biology (ISMB-97)

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Molecular evolution and phylogenetics
a tutorial
Marcella McClure

The purpose of this tutorial is to provide the student with an introductory survey of the field of molecular evolution. Molecular evolution is the study of the evolution of biologically active molecules and the reconstruction of their history. This study begins with the transition from the non-living, chemical state to a biological, living state, and continues with the history of life at the molecular level, as it presently exists.

Historically molecular evolution has been defined by population geneticists as the study of the fixation of genes in populations and the reconstruction of the phylogenetic history of genes. With the plethora of studies over the last 25 years on the origins of biologically active molecules, the advent of the biotechnological revolution in nucleic acid sequencing techniques, and the discovery of specific RNA molecules that perform catalysis the definition of molecular evolution has expanded. There are basically six areas in the study of molecular evolution:

  1. the origin of life, biogenesis;
  2. the RNA world as intermediary to the DNA-based one;
  3. population genetics;
  4. phylogenetic reconstruction of genes and genomes;
  5. molecular pattern recognition, the identification of sequence patterns conferring function in proteins and nucleic acids; and
  6. the mechanisms of the evolutionary process.

The last three fields are very active areas of research given the rapidly expanding sequence and structure databases. We will briefly cover the basics of biogenesis and the RNA world. Major emphasis will be on the concepts and methods used to analyze genes and genomes, and the mechanisms of gene and genome evolution.