Transgenerational Continuity: Integrating Genomic and Epigenetic Layers of Biological Persistence

Transgenerational continuity (TC) describes the persistence of inherited genomic and regulatory architectures across generations. Progress in identity-by-descent (IBD) detection, recombination dynamics, and epigenetic research highlights the growing need for a more comprehensive model of inheritance. This theoretical framework synthesizes evidence from genomics, population studies, and epigenetics to outline how inherited genomic and regulatory architectures, which are transmitted through IBD, together with heritable epigenetic modifications, can preserve ancestral information across generations. Within the genomic layer, IBD captures continuity across three nested scales, where recent familial segments link close relatives, population-level haplotypes are shared across cohorts, and archaic fragments from Neanderthal and Denisovan admixture persist as molecular fossils of ancient lineages. Although recombination and selection reshape these regions, their persistence across time scales highlights the evolutionary durability of genomic continuity. The epigenetic layer, in turn, reflects regulatory persistence through molecular modifications, that transmit functional states across generations even when DNA sequence itself remains unchanged. These layers are partially intertwined, as recombination links genomic and epigenetic inheritance by shaping the genomic context of epigenetic marks, such as genomic imprinting. Together, these mechanisms suggest that inheritance encompasses not only DNA sequence, but also the persistence of regulatory states. In this perspective, evolutionary dynamics arise not only from the generation of variation, but also from selection, which acts on the persistence of inherited molecular architectures across generations. Transgenerational continuity therefore integrates genetic and epigenetic inheritance into a multi-scale architecture of persistence, that allows biological identity to extend across generations and evolutionary time.