Morphological and Molecular Data from Phylogenies PDF

MORPHOLOGICAL AND MOLECULAR DATA FROM PHYLOGENIES Lesson 2.1  Key Terms Character – it is a well- defined feature in a taxonomic unit; any observable feature, or trait, of an organism, whether acquired or inherited. Character state – value of the character; mutually exclusive features among t...

MORPHOLOGICAL AND MOLECULAR DATA FROM PHYLOGENIES Lesson 2.1  Key Terms Character – it is a well- defined feature in a taxonomic unit; any observable feature, or trait, of an organism, whether acquired or inherited. Character state – value of the character; mutually exclusive features among taxa of a single paralog-equivalent assemblage that exhibit orthologous relationships to each other. Example: Hair – Character Present or Absent – Character state  MORPHOLOGICAL DATA How to Distinguish: Homologies from Analogies?  Morphological Data How to Distinguish: Homologies from Analogies? *Comparing fossil evidence and the degree of complexity The more elements that are similar in two complex structures, the more LIKELY it is that they are HOMOLOGOUS Analogous (Homoplasy) features share similar function, but not common ancestry Homologous features share common ancestry, but not Based on the cladogram: o Which morphological characters and data were used in constructing the cladogram? ______________________________________ ______________________________________ o What is the character state of the character, shell? ______________________________________ ______________________________________ o What is the basal taxon/lineage of Fossarininae? ______________________________________ ______________________________________ o What is the autapomorphy of Broderipia and Roya? ______________________________________ ______________________________________ o What is the synapomorphy of Broderipia and Roya? ______________________________________ ______________________________________ o What can you infer from the entire cladogram? ______________________________________ Molecular Data Cladograms of Metazoans. Morphological phylogeny based on morphology and embryology (A), and molecular phylogeny based on  Compare the positions and groups belonging to Deuterostomes and Protostomes clades in Figure above. __________________________ What can you infer from the two cladograms? Apart from rRNA, there are other sources of molecular data for phylogenetic studies: cytochrome c oxidase I (COI) gene. COI gene sequence is used for animal barcoding since COI is present and plays an important role in the electron transport chain in animals. Recently, COI has been suggested to have the potential for insect identification (Patwardhan et al., 2014). cytochrome-b gene. Cytochrome-b gene sequence is also used for animal barcoding. It is known to be most useful in recovering phylogenetic relationships of closely-related taxa but loses resolution at deeper nodes (Patwardhan et al., rbcL 2014)gene. rbcL gene is located in the chloroplast genome and is universal to all plants, thus used for plant barcoding. matK gene. matK gene is located within the chloroplast genome and is also used for plant barcoding (Patwardhan et al., 2014). Morphological Data Molecular Data  MOLECULAR DATA LESSON 2.1 Part 2 Characters DATA Distances TYPES  Key Terms Character – it is a well- defined feature in a taxonomic unit; any observable feature, or trait, of an organism, whether acquired or inherited. Character state – value of the character; mutually exclusive features among taxa of a single paralog- equivalent assemblage that exhibit orthologous relationships Example: Hairto each other. – Character Present or Absent – Character state Character – Position 195 Character state – A in Oryctolagus cuniculus DISTANCES Fraction of mismatches at aligned positions Quantitative statement concerning the DISSIMILARITY  Inferring Evolutionary History and Relationships of Organisms *Phylogenies as hypotheses *We can make and test predictions *Phylogenetic bracketing – we can predict that features shared by two groups of closely related THANK YOU