Which component of the mitochondrial genome showed the slowest rate of evolution among the analyzed Lycosidae species?
The COX1 gene.
Despite significant behavioral and geographical diversification across the Lycosidae family, the core genetic blueprint contained within the mitochondrial genome has remained remarkably stable in certain aspects. Molecular analysis of 56 species indicated that, generally, the protein-coding genes (PCGs) experienced weak selection pressure, quantifiable by a ratio of $ ext{Ka}/ ext{Ks}$ less than 1. However, when comparing the rates of evolution across these essential genes, the $ ext{COX1}$ gene stood out. This specific gene displayed the slowest rate of evolutionary change among all the analyzed protein-coding genes, suggesting strong purifying selection maintaining its function across the diverse lineages of wolf spiders. This stability in PCGs contrasts with the observed mobility of other elements, like tRNAs, in the organization of the mitochondrial DNA, particularly in basal groups.
