Denisovans' Genetic Legacy Might Have Influenced Our Mental Health
A specific genetic variant related to zinc regulation, possibly providing an evolutionary advantage for our ancestors adapting to cold environments may have affected mental health
In a groundbreaking study led by the Institute of Evolutionary Biology (IBE) and Pompeu Fabra University (UPF), scientists have unraveled one of the most significant genetic contributions by Denisovans to modern humans. Published in PLoS Genetics1, the research highlights a specific genetic variant linked to zinc regulation, shedding light on its evolutionary advantage for our ancestors adapting to cold environments. Modern humans, upon leaving Africa 60,000 years ago, encountered Denisovans in Asia, resulting in complex interactions and crossbreeding. These interactions have left a lasting mark on our genetic makeup, influencing our ability to adapt to diverse climates and potentially impacting our mental health.
When modern humans ventured into Eurasia, they met Denisovans, an ancient hominin species. Today, remnants of Denisovan DNA are present in various human populations, serving as a testament to these initial encounters. In a collaborative effort, researchers from IBE and UPF have identified a genetic adaptation from Denisovans that aided ancestral humans in adapting to cold environments. This adaptation, involving zinc regulation, provided an evolutionary advantage. However, the same genetic variation has also been associated with a predisposition to neuropsychiatric disorders such as depression and schizophrenia in modern humans.
The study focused on a specific genetic variant in the SLC30A9 gene, derived from Denisovan interbreeding. This variant, connected to zinc regulation, proved to be beneficial for our ancestors, likely offering an advantage in coping with colder climates. The change in amino acids within the zinc transporter affected cellular zinc balance, leading to alterations in cell metabolism. This adaptation potentially allowed ancient humans to thrive in harsh environments. However, this genetic variation also had implications for mental health, increasing susceptibility to various psychiatric disorders.
Remarkably, this Denisovan genetic adaptation is widespread across non-African populations, affecting individuals in Europe, Asia, and the Americas. While other Denisovan genetic variants are region-specific, this zinc regulation adaptation is exceptional in its global prevalence. Future research, potentially involving animal models, could provide deeper insights into the genetic predispositions to mental illnesses linked to this Denisovan heritage. The study underscores the intricate tapestry of human evolution, revealing both our adaptability and the complexities of our shared genetic history. As scientists delve further into these genetic legacies, humanity gains a deeper understanding of its ancient past and the forces that have shaped our diverse existence.
Roca-Umbert, A., Garcia-Calleja, J., Vogel-González, M., Fierro-Villegas, A., Ill-Raga, G., Herrera-Fernández, V., Bosnjak, A., Muntané, G., Gutiérrez, E., Campelo, F., Vicente, R., & Bosch, E. (2023). Human genetic adaptation related to cellular zinc homeostasis. PLoS Genetics, 19(9), e1010950. https://doi.org/10.1371/journal.pgen.1010950