Essential knowledge 1.B.1:Organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.

Structural and functional evidence supports the relatedness of all domains•Can you think of any evidences that

support the claim that all living things are related?

Evidence #1: Major features of the genetic code are shared by all modern living systems

Evidence #2 DNA and RNA are carriers of genetic information through transcription, translation and replication.

Evidence #3: Metabolic pathways are conserved across all currently recognized domains.

http://genome.cshlp.org/content/13/3/422.long Scientific study to support the claim. Have student read the article and discuss in class. Abstract is on the following slide

http://www.salk.edu/news/pressrelease_details.php?press_id=484 A second article supporting evidence #3

The Phylogenetic Extent of Metabolic Enzymes and PathwaysJosé Manuel Peregrin-Alvarez, Sophia Tsoka, and Christos A. Ouzounis1Computational Genomics Group, The European Bioinformatics Institute, EMBL Cambridge Outstation, Cambridge CB10 1SD, UK

AbstractThe evolution of metabolic enzymes and pathways has been a subject of intense study for more than half a century. Yet, so far, previous studies have focused on a small number of enzyme families or biochemical pathways. Here, we examine the phylogenetic distribution of the full-known metabolic complement of Escherichia coli, using sequence comparison against taxa-specific databases. Half of the metabolic enzymes have homologs in all domains of life, representing families involved in some of the most fundamental cellular processes. We thus show for the first time and in a comprehensive way that metabolism is conserved at the enzyme level. In addition, our analysis suggests that despite the sequence conservation and the extensive phylogenetic distribution of metabolic enzymes, their groupings into biochemical pathways are much more variable than previously thought.

Structural evidence supports the relatedness of all eukaryotes.•How similar are you to a banana?•Answer: Very closely related

Example 1: Cytoskeleton (a network of structural proteins that facilitate cell movement, morphological integrity and organelle transport)

Example 2: Membrane-bound organelles (mitochondria and/or chloroplasts)

Example 3: Linear chromosomes

Example 4: Endomembrane systems, including the nuclear envelope