A set of living fossil specimens discloses crucial information about the evolution of cognition genes

Cognitions in animals (including humans) have a genetic basis. From early marine fish to subsequently emerging and increasingly advanced animal groups, cognitive functions (including language) clearly exhibit a trend toward greater complexity, yet also present numerous highly complex and challenging scenarios to interpret. This complexity arises because the evolutionary trajectory of gene clusters associated with cognitive functions displays highly intricate ecological characteristics across different animal groups. In this study, the authors examined nearly 500 samples from diverse animal groups, encompassing major common categories such as ancient humans, modern humans, fish, amphibians, reptiles, birds, rodents, Laurasiatheria, and primates—with a particular focus on a set of living fossil samples (primarily concentrated among amphibians and reptiles). Through cluster analysis of approximately 2,300 single nucleotide variants (SNVs) from 33 cognitive genes, the study revealed that the fundamental framework of genes related to cognitive ability likely already existed during the transition from fish to amphibians and reptiles. Furthermore, living fossil samples—occupying an evolutionary position bridging fish and more advanced animal groups beyond reptiles—provide critical detailed evidence by spanning the gap between fish and the approximate evolutionary origins of primates. This evidence strongly suggests that the origin and evolutionary pathway of human cognitive gene polymorphism patterns seem significantly distinct from those of primates.