BIOL 336 Lecture Notes - Lecture 13: Nonsynonymous Substitution, Synonymous Substitution, Molecular Clock
Document Summary
Specific enzymes that allow bar-headed geese to utilize oxygen and exert itself at high altitudes (changes in. Aa sequence of enzyme allow geese to use oxygen at high altitudes (even though o2 levels are low) Neutral theory: idea that most substitutions in dna and aa sequence of proteins are driven by genetic drift. Nonsynonymous substitution: a substitution (i. e. fixation of a mutation) that changes the aa sequence of a. One model of molecular evolution: proteins stay pretty much same, but occasionally change a lot when. Molecular clock: mutations substitute in a protein at a roughly constant rate. Mutation in individuals (chance of mutation occurring at each replication) 0: no ns changes tolerated, only seeing ns (strongly purifying selection selection that removes deleterious mutants, preventing change) 1: ns occurs as often as s (maybe no selection) we might be able to infer gene is either not really used or expressed. >3: ds could be changing mutations back, meaning dn is smaller.
