Trowsdale, A. T. | bioRxiv Science

bioRxiv2026

Parental care is a genetic capacitor

Parental care is widespread across the animal kingdom and plays a critical role in offspring development. Yet, its broader genetic and evolutionary impacts remain underexplored. Here, using the biparental burying beetle Nicrophorus vespilloides as a model, we show that parental care acts as a genetic capacitor: it allows genetic variation to accumulate while care is present and releases it when care is disrupted. By experimentally manipulating care, we demonstrate that parental care suppresses genetic variation associated with offspring body size, which is released when care is lost. To investigate the underlying molecular mechanisms, we generate a chromosome-scale genome assembly for N. vespilloides, alongside a single-nucleus gene expression atlas and epigenomic datasets from larvae reared with and without parental care. We find that the loss of parental care induces molecular stress, disrupting the expression of the protein chaperone Hsp83, which is a well-known molecular capacitor, alongside other putative mRNA chaperones. Moreover, our results suggest that parental care buffers development by maintaining an open, responsive chromatin landscape and redundant gene regulatory interactions. Overall, our work reveals that parental care shapes the storage, expression and release of genetic variation with broad implications for adaptation and evolution.

animal behavior and cognition↗

bioRxiv2023

Parental care drives the evolution of molecular genetic variation

Cooperative social behaviours, such as parental care, have long been hypothesized to relax selection leading to the accumulation of genetic variation in populations. Although the idea has been discussed for decades, there has been relatively little experimental work to investigate how social behaviour contributes to genetic variation in populations. Here, we investigate how parental care can shape molecular genetic variation in the subsocial insect Nicrophorus vespilloides. Using whole genome sequencing of populations that had evolved in the presence or absence of parental care for 30 generations, we show that parental care maintains levels of standing genetic variation. In contrast, under a harsh environment without care, strong directional selection caused a reduction in genetic variation. Furthermore, we show that adaptation to the loss of care is associated with genetic divergence between populations at loci related to stress, morphological development and transcriptional regulation. These data reveal how social behaviour is linked to the genetic processes that shape and maintain genetic diversity within populations, and provides rare empirical evidence for an old hypothesis. Lay SummarySocial behaviours, such as parental care, have long been hypothesized to result in the accumulation of genetic variation in populations. Here, we investigate how parental care can shape molecular genetic variation in a species that perform biparental care, Nicrophorus vespilloides. Using genome sequencing of populations that had evolved in the presence or absence of parental care for 30 generations, we show that parental care maintains levels of standing genetic variation. In contrast, under a harsh environment without care, populations lost genetic variation. Furthermore, we show that adaptation to the loss of care is associated with genetic divergence between populations at genes related to stress, morphological development and transcriptional regulation. These data reveal how social behaviour is linked to the genetic processes that shape and maintain genetic diversity within populations.

evolutionary biology↗