Biology subjects

Casten, L. G.

Publications and source records attributed to Casten, L. G..

3 recordsLinked to original sources

bioRxiv2026

Migration genetics link excitatory neurons to ancient selection and economic growth

From ancient nomadic movements to modern urbanization, migration has driven human history through mechanisms that remain poorly understood. We conducted a genome-wide association study of migration distance in 250,000 UK individuals, identifying 20 loci in neurodevelopmental genes with 5% heritability. Migration-related variants are associated with excitatory neuron gene expression and correlate with cognition, risk-tolerance, and reduced interpersonal attachment. Within-family analyses demonstrate genetic effects remain significant after controlling for shared environmental factors between siblings. Our polygenic score predicts inferred mobility in >1,000 ancient individuals spanning 10,000 years, revealing positive selection on migration alleles that increased substantially over millennia. At the population level, each standard deviation increase in county-level migration polygenic score predicts >$4,000 greater income growth per person in the US. These findings establish migration as a heritable trait and suggest biological pathways connecting individual neurodevelopment with regional prosperity across evolutionary and contemporary timescales.

genomics↗

bioRxiv2025

Rapidly evolved genomic regions shape individual language abilities in present-day humans

Language is a defining feature of our species, yet the genomic changes enabling it remain poorly understood. Despite decades of work since FOXP2s discovery, we still lack a clear picture of which regions shaped language evolution and how variation contributes to present-day phenotypic differences. Using a novel evolutionary stratified polygenic score approach in nearly 40,000 individuals, we find that Human Ancestor Quickly Evolved Regions (HAQERs) are specifically associated with language but not general cognition. HAQERs evolved before the human-Neanderthal split, giving hominins increased binding of Forkhead and Homeobox transcription factors, and show balancing selection across the past 20,000 years. Remarkably, language variants in HAQERs appear more prevalent in Neanderthals and have convergently evolved across vocal-learning mammals. Our results reveal how ancient innovations continue shaping human language.

evolutionary biology↗

bioRxiv2023

Cerebellar Morphological Differences in Bipolar Disorder Type I

BackgroundThe neural underpinnings of bipolar disorder (BD) remain poorly understood. The cerebellum is ideally positioned to modulate emotional regulation circuitry yet has been understudied in BD. Previous studies have suggested differences in cerebellar activity and metabolism in BD, however findings on cerebellar structural differences remain contradictory. MethodsWe collected 3T anatomical MRI scans from participants with (N = 131) and without (N = 81) BD type I. Differences in cerebellar volumes were assessed along with factors that influence the results. ResultsThe cerebellar cortex was smaller bilaterally in participants with BD. Polygenic propensity score (bipolar N = 103, control N = 64) did not predict any cerebellar volumes, suggesting that non-genetic factors may have greater influence on the cerebellar volume difference we observed in BD. Cerebellar white matter volumes increased with more adverse childhood events, but we did not observe any associations with parental psychiatric illness. We also evaluated time from onset and symptom burden and found no associations with cerebellar volumes, suggesting neurodevelopment may differ prior to onset. Finally, we found taking sedatives was associated with larger cerebellar white matter and non-significantly larger cortical volume. LimitationsThis study was cross-sectional, limiting interpretation of possible mechanisms. Most of our participants were White, which could limit the generalizability. Additionally, we did not account for potential polypharmacy interactions. ConclusionsThese findings suggest that external influences, such as medications, may influence cerebellum structure in BD and may mask underlying differences. Accounting for medication may be critical for consistent findings in future studies.

neuroscience↗