The Evolution of Cognitive Abilities in Marine Animals: Insights from Cognition Gene Polymorphism in Coelacanths and Lungfish

Both coelacanths and lungfish have fossil evidence dating back 400 million years, placing them at a critical evolutionary juncture when marine animals have transitioned to terrestrial environments. An intriguing question lies in the extent to which their cognitive abilities had evolved before they crawled onto land. While no fossil DNA exist for extinct coelacanths or lungfish, studies on their extant species offer clues. Notably, the biological traits of coelacanths and lungfish have been remarkably stable over the past 70 million years, suggesting exceptional stability in their genomic sequences as well. This raises the possibility of inferring their cognition gene polymorphism patterns (CGPP) and evolutionary positioning through genomic analyses of modern samples. Comparative analyses with a range of animal taxa and human samples revealed that the CGPP of both coelacanths and lungfish are evolutionarily closer to those of archaic humans than those of most other animal groups. The CGPP appears to occupy an evolutionary inflection point bridging diverse animal lineages to archaic humans.