Slow Evolution of rag1 and pomc Genes in Vertebrates with Large Genomes

TL;DR

This study compares evolutionary rates of specific genes across vertebrate lineages, revealing significant rate variations linked to habitat and lineage differences, with implications for understanding vertebrate genome evolution.

Contribution

It provides a comparative analysis of neutral and non-neutral substitution rates in vertebrates, highlighting lineage-specific rate differences and their potential ecological explanations.

Findings

Fish show faster evolution in tetraodontiformes than cypriniformes.

Cypriniformes evolve faster than elasmobranchs.

Salamanders in Plethodontidae evolve nearly twice as fast as Hydromantes.

Abstract

Growing evidence suggests that many vertebrate lineages are evolving at significantly different rates. As a first approximation of evolutionary rates, we assessed the amount of neutral (dS) and non-neutral (dN) substitutions that have accumulated within and across sister clades since the time of their divergence. We found that in fish, tetraodontiformes (pufferfish) are evolving at faster rates than cypriniformes (fresh water teleosts), while cypriniformes are evolving faster than elasmobranchs (sharks, skates and rays). A similar rate variation was observed in salamanders: plethodontidae were found to evolve at a rate nearly two fold faster than the hydromantes lineage. We discuss possible explanations for this striking variation in substitution rates among different vertebrate lineages that occupy widely diverse habitats and niches.