Genomic Insights Into the Body Size Evolution in Felidae (Mammalia: Carnivora).

Body size represents one of the most fundamental adaptive traits in mammals, but the genetic architecture underlying the extensive body size diversification observed in the Felidae family remains largely uncharacterized. Here, we present the first comprehensive comparative genomic analysis of Felidae body size evolution using high-quality reference genomes from 17 species, including two newly reannotated genomes. Using phylogenetic generalized least squares (PGLS) analysis, we identified 35 body-size-associated genes (BAGs), most of which are functionally implicated in skeletal development, thyroid hormone synthesis, and lipid metabolism. Functional enrichment analysis revealed that positively selected genes (PSGs) in large-bodied Felidae were predominantly enriched in DNA repair pathways, whereas PSGs in small-bodied Felidae were primarily involved in energy metabolism and lipid metabolism processes. In summary, the adaptive evolution of both core signaling pathways and key functional genes has jointly driven body size diversification in Felidae. This study uncovers new molecular insights into how mammalian body size evolves, while also generating a valuable genomic dataset for subsequent functional research.