Estimation of Genome Evolution Time by Mutation Rate

Abstract

Mutations, transposable elements, and recombination are the main mechanisms for genome size evolution. The quantitative impact of mutations, excluding polyploidy, on genome size is well studied in some genomes while the impact of other factors has not been investigated. Mutation rate was used to estimate the evolution time of origin genome to form a higher size genome and test if the estimated age of earth fits for these evolution events. Results indicated that the evolution time of the smallest detected genome through mutation rate to the largest detected genome is much higher than the estimated age of earth. The cumulative evolution time of the studied origin genomes was estimated at 5300 folds of earth's age and the average evolution time is 2.7 × 1012 years per genome. The relationship among genome size, mutation rate, and evolution time indicated that evolution time is positively correlated with genome size suggesting that larger genomes take longer time to evolve in size. Estimation of evolution time would lead to establishment of genome evolution timeline to replace or support the fossil evolution timeline.