A new bioRxiv preprint reports that a small subset of Neanderthal-derived genetic variants still affects brain structure in present-day humans, even though many archaic variants appear to have been removed over time by selection.
Using genetic and MRI data, the authors argue that surviving introgressed alleles continue to influence both neuroanatomy and psychiatric risk.
They tested whether Neanderthal-derived alleles were associated with structural features of the brain, including cortical and subcortical measurements.
According to the authors, the overall polygenic signal was associated with protection against schizophrenia but with increased genetic liability for major depression.
Using genetic and MRI data, the authors argue that surviving introgressed alleles continue to influence both neuroanatomy and psychiatric risk.
What the study looked at
The researchers examined 370 brain imaging traits derived from MRI scans in nearly 40,000 UK Biobank participants.They tested whether Neanderthal-derived alleles were associated with structural features of the brain, including cortical and subcortical measurements.
Main findings
- Low-frequency introgressed variants showed depleted effects on brain phenotypes, which the authors interpret as evidence that many archaic influences were likely purged over evolutionary time.
- So-called “Neanderthal deserts” showed enrichment for functional effects in the modern brain.
- The frontal and parietal regions were among the most consistently affected areas.
- The study fine-mapped eight associations to introgressed variants, including a notable signal near DAAM1 linked to the cuneus and precuneus.
Mental health angle
The paper also suggests that these inherited Neanderthal variants are relevant to neuropsychiatric traits, not just brain anatomy.According to the authors, the overall polygenic signal was associated with protection against schizophrenia but with increased genetic liability for major depression.