Mammalian genome evolution is governed by multiple pacemakers

Area of Science:

• Evolutionary biology
• Genomics
• Phylogenetics

Background:

• Genomic evolution is driven by mutation, selection, and genetic drift, causing rate variation across genes and lineages.
• Interactions between these variations can lead to residual effects, where rate heterogeneity patterns differ across genes.
• Pacemaker models describe genome evolution rate variation, differing in the significance of residual effects: Universal, Multiple, and Degenerate Multiple Pacemaker models.

Purpose of the Study:

• To compare different pacemaker models of genome evolution.
• To partition and analyze rate variation across loci using a phylogenetic method.
• To investigate the factors driving genomic evolution and inform molecular-clock analyses.

Main Methods:

• Phylogenetic analysis to partition evolutionary rate variation across loci.
• Comparison of Universal, Multiple, and Degenerate Multiple Pacemaker models.
• Analysis of 431 genes from 29 mammalian taxa.

Main Results:

• The study identified 13 distinct pacemakers, supporting the Multiple Pacemaker model of genome evolution.
• Rate variation across the analyzed mammalian genes is explained by these 13 pacemakers.
• No correlation was found between identified pacemakers and specific gene functions.

Conclusions:

• The Multiple Pacemaker model best explains the observed rate variation in mammalian genome evolution.
• The findings provide insights into the complex factors shaping genomic evolution.
• Results have implications for the accuracy and interpretation of molecular-clock dating.