4.1 Mutation Rates

 I believe that mutation rate can evolve. Evolution depends on genetic differences among individuals and species, and there are many ways DNA can change. One of the reasons why DNA changes is from mutation rates. Mutations can vary between individuals and species from an inborn system that could possibly be passed down to the offspring if they are heritable. Mutations can even come from the outside environment, like natural chemicals, sun exposure, and much more. High mutation rates evolve and they create more variation in the gene pool. From the book, “The Princeton Guide to Evolution," it states, “without mutation, every locus will ultimately fix, the population will be devoid of genetic variation, and evolution will cease.” 

Technological advances have given sciences a very large insight into the different variations of genomes. Variation of the genome is introduced through mutations and can affect phenotypic expression, natural selection, and fitness levels. Mutations can result in the change of a nucleotide sequence in the genome, be the source of genetic variation, new alleles, new genes, change in gene regulation, and so much more. In the class Evolution, I learned that there is about 7.8 billion humans on earth, and the human genome is about 3,200 Mb and 35,000 genomes. With this, there is about 12 billion mutations in the human population. There can be 100,000 of folds in mutation rates in the genome per generation. So species that have larger genomes, on average, have a higher mutation rate simply because there might be more mistakes as you copy a larger genome. They are really driven my differences in body size, and a larger difference between unicellular and multicellular species. For unicellular organisms, every cell division is a start for a new generation, while multicellular organisms they go through many rounds of cell division before their genes is passed on. But every round of development can introduce more mutations. This is why multicellular organisms, and especially those in larger size, will have a high mutation rate and unicellular organisms will have low mutation rates. High fitness from an individual would also show low mutation rates. An important thing to remember is that the number of mutations introduced in a population is not only reflected by the mutation rate but also by the population size. In the “Princeton Guide to Evolution,” it states, “evolution requires variation, all else equal, the more genetic variation produced by mutation, the more opportunity for evolution, and the faster evolution can proceed.” Evolution and mutation does come with a cost, and can be either good or bad for an individual. 

The Princeton Guide to Evolution, edited by David A. Baum, et al., Princeton University Press, 2013. ProQuest Ebook Central, https://ebookcentral-proquest-com.er.lib.k-state.edu/lib/ksu/detail.action?docID=1372264.