A new study reconstructs the evolutionary timelines of human brain, cognition, and behavioral traits, revealing when key genetic variants influencing intelligence and psychiatric vulnerability emerged.
New research published in Cerebral Cortex https://academic.oup.com/cercor/article/35/8/bhaf127/8233140 reveals that many of the genetic changes that shaped the human brain and cognition, and even our vulnerability to mental illness, are surprisingly recent in evolutionary history.
The study, led by Ilan Libedinsky and Martijn van den Heuvel from the Complex Trait Genetics lab at CNCR, combined genomic dating methods with data from over 2,500 genome-wide association studies. This approach enabled the researchers to reconstruct evolutionary timelines for traits that cannot be studied through paleontological records, such as brain structure, cognition, and behavior, providing a genetic window into how humans have evolved over the past five million years.
Genes with these recent evolutionary modifications were linked to cortical structure, neuronal development, and intelligence. The same “young” genes were also highly expressed in brain regions involved in language, suggesting that evolutionary recent genetic modifications helped refine the neural circuits underlying complex cognition and communication, hallmarks of the human species. Some of these recent genetic changes were also associated with psychiatric disorders such as depression and schizophrenia.
By tracing when and where genetic variants emerged, the study opens new opportunities to investigate how evolutionary pressures on human-specific traits have shaped the molecular mechanisms underlying brain function and vulnerability.