BSCI 207 Lecture Notes - Lecture 3: Gene Duplication, Horizontal Gene Transfer, Ribosomal Rna
3 Sep 2016
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Document Summary
Many kinds of molecular data sequence: dna / rna / amino acids. The more similar two sequences, the more recently the two taxa had a common ancestor. Rate of change depends on how fast sequences mutate. How strong selection acts to keep sequence the same. Some sequences are very strongly selected to stay the same: exonic dna that specifies amino acids (1st and 2nd positions of codon, certain proteins that are critical to organismal function, histones, ribosomal rna. Prokaryote phylogeny: morphologies of prokaryotes are very similar, hard to determine phylogenetic relationships using morphology, had to await molecular revolution of 1970s, woese"s interest, identify the eukaryote ancestor, understand prokaryotic evolution, determine the ancestral gene families. Iwabe et al 1989 used duplicated genes: used two gene pairs to test this idea, elongation factor tu and g, f1atpase and . Luca organisms: lateral transfer of some key genes.
