Biology 1002B Lecture Notes - Lecture 24: Hoatzin, Rhodopsin, Lysozyme
31 May 2016
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Neutral theory of molecular evolution: all mutations would affect fitness (mostly deleterious, some advantageous) Selection theory: mutations could be advantageous, neutral, or deleterious. The molecular clock: if the neutral theory is correct then the number of mutations should be proportional to the time since divergence, rate of substitution of genes is occurring at a fairly constant rate. Synonymous vs non-synonymous rate: synonymous has a much higher rate/slope. Silent substitution: non-synonymous has a lower rate/slope. Replacement substitution: happens because non-synonymous mutations change phenotype and are selected for more likely to not be fit (deleterious) How predictable is evolution: if we could travel back in time 4 billion years and make a few changes, what would remain the same upon our return. The idea that each step in evolution is dependent on all the steps before it (gould: convergence . The evolutionary routes are many, but the destinations are limited (simon conway-morris)
